HEALTH & SAFETY GENERAL INFORMATION
This section provides access to a library of HS&E information developed to provide practical guidance and advice to our customers. The content covers a wide range of topics including environmental controls over manufacturing processes, chemical hazards, fire, selection of personal protective equipment, and environmental considerations relating to used or waste product. This information reflects the most up to date opinion on HS&E issues relevant to a diverse product range distributed to a global market.
If you are looking for Safety Data Sheets (Known as SDS or MSDS) click HERE to go to the Safety Data Sheet selection page.
Health Safety & Environmental Management System
Health, Safety & Environmental Policies
Health & Safety Policy
Environmental Protection Policy
Product Safety Policy
Energy Conservation Policy
Mobberley site Environmental Facts
Photography and your Health
How Photographic Chemicals can Enter Your Body
How Photographic Chemicals can Affect Your Body
How Exposure to Photographic Chemicals can be Controlled
Safe Working Practices
Pregnant and Breast Feeding Women
Special Hazards - Hydroquinone
Special Hazards – Sulphur Dioxide
Chemical Hazard Communication
Global Harmonisation For Supply (GHS)
Information on Product Labels
Information on Safety Data Sheets
Availability of Safety Data Sheets
Safety Data Sheets – A Simple User Guide and Glossary
Health & Safety Information for Coated Products
Composition Of Film and Paper
Toxicity of Films and Papers
The Fire Classification and Burning Characteristics of Films and Papers
Fire Classifications of ILFORD PHOTO Products
Burning Characteristics of ILFORD PHOTO Products
Waste and Disposal
Coated Films and Papers
Chemicals and Processing Solutions
Waste Disposal and Septic Tank Systems
Oxygen Demand of Effluents
Permits to discharge
Electrolytic Silver Recovery
Solution Re-Use & Recycling
Wash Water Recycling
Reducing Wash Water
At HARMAN technology Ltd, all Health Safety and Environmental issues, in fields ranging from product design and the operation of the manufacturing processes to the packaging and labelling of individual products, fall within the remit of the Health Safety and Environment Management Committee (HSEMC). The HSEMC meets 6 times per year.
The HARMAN technology Ltd quality management system is registered as complying with ISO 9001:2008. The Health Safety & Environmental Management System is operated as a parallel system using the management principles of ISO9001.
Health and safety performance on the Mobberley manufacturing site has been recognised since 1985 by the Royal Society for the Prevention of Accidents with the presentation of numerous awards. In April 2011 HARMAN technology Ltd won the RoSPA Order of Distinction in recognition of 20 consecutive years of excellence in health and safety.
HARMAN technology Ltd has developed and approved 4 key policies that underpin the Company’s approach to managing health, safety and environmental issues.
These relate to:
- Occupational health & safety in the workplace.
- Minimisation of the environmental impact of products and manufacturing processes.
- Compliance of products with relevant HS&E legislation in countries where they are sold.
- Optimisation of effectiveness in energy conservation.
These policies are set out below.
HARMAN technology will:
1.Develop an organisation and culture that secures everybody's participation and consult with employees to ensure the health and safety of all.
2.Promote health and safety at work as an essential function of good management and require everybody to consider their responsibilities in this field as equal to their responsibilities in others.
3.Establish risk assessment and control as the foundation of the H&S management system and set legal duties as the minimum standard for achievement.
4.Make arrangements for health and safety that protect employee welfare, contribute to business performance and fulfil both the spirit and the letter of the law.
5.Appoint competent people to help with the implementation of these arrangements and provide information, instruction and training to all those working on our premises.
Peter Elton, Director, Health, Safety and Environmental Protection
It is the policy of HARMAN technology Ltd to take all reasonable measures to protect the environment from any adverse effects that its activities might have.
1.Take all reasonable measures in the design, construction, operation, and maintenance of our plant, equipment, and facilities to reduce any adverse effects which our operations might have upon the environment;
2.Devote as much attention and effort to preventing pollution and safeguarding environmental matters in all our activities as to matters of economy and productivity;
3.Identify and investigate environmental matters in a professional manner, with assistance from professional advisors when necessary;
4.Provide the necessary instructions, equipment, and training to enable our employees to carry out their duties in an environmentally safe manner;
5.Make every effort, commensurate with the most recent scientific knowledge available, to ensure that our products will not have untoward effects on the environment; and
6.Maintain an environmental protection organisation which will seek continuous improvement, develop and administer methods and procedures, and co-ordinate all efforts to secure fulfilment of this policy.
Peter Elton, Director, Health, Safety and Environmental Protection
It is the policy of HARMAN technology Ltd to act responsibly and to take all necessary measures to protect the customer and the environment by ensuring that its products are safe and comply with the appropriate health, safety, and environmental legislation in each country into which these products are sold.
1.Maintain an awareness of and ensure compliance with international product, health, safety, and environmental regulations and requirements.
2.Take necessary measures in the design, manufacture, and marketing of our products to protect the environment and prevent personal injury.
3.Identify responsibilities and accountabilities for the management and implementation of policies designed to ensure product safety.
4.Provide the necessary instructions, equipment, and training to enable our employees to carry out their duties consistently with this policy.
5.Maintain an organisation that will develop and administer methods and procedures and co-ordinate the efforts required to secure fulfilment of this policy.
Howard Hopwood, Chairman
It is the policy of HARMAN technology Ltd to maintain throughout our operations a commitment to energy conservation.
1.Take full account of energy resources, and use these efficiently and economically, reflecting best industry practice, thereby contributing to an improved environment.
2.Ensure good management of energy resources in all our manufacturing and administrative areas.
3.Ensure all staff and suppliers are involved in the energy saving process and understand energy saving techniques in the context of the business.
4.Assess the likely effects of planned projects and operations on energy utilisation and consequently their environmental impact.
5.Set performance targets and report to employees how well those targets have been met.
Peter Elton, Director, Health, Safety and Environmental Protection
HARMAN technology Ltd has never tested any photochemical product (e.g. developer or fixer) on animals.
The company has had animal testing done in the past (where required by law) for a very small number of chemicals used in the manufacture of its products. Wherever possible, we use existing, well characterised chemicals, since this allows us to make use of existing and available toxicological data.
In those rare cases where animal test data may be required in future so as to comply with the law (such as in connection with the REACH Regulation):
1.Testing will only be commissioned from accredited test laboratories.
2.It will only be commissioned as a last resort, when all alternative sources of data have been exhausted – in fact, this is now a legal requirement.
3.It will be restricted to the minimum required by law.
The HARMAN technology manufacturing plant at Mobberley in the UK is situated in the Cheshire countryside. As a consequence we have made, and will continue to make, as required, significant investments in order to minimise waste and prevent pollution of the local environment.
VOC (solvent) emissions to the air are controlled by the Local Authority under LAPPC permit. Emulsion making and small scale chemical manufacturing activities are controlled by the Environment Agency under IPPC permit.
We also have our own on site effluent treatment plant and its emissions are controlled and monitored by the local sewerage undertaking. Facts:
·Each of the main streams of liquid waste has its own dedicated drainage system
·The site drains are mapped and labelled to reduce the risk of contamination in the event of a spillage
·In the event of a major incident, the flow of surface water leaving the site can be stopped and contained
·Outside normal working hours, a Crisis Controller is always available for call-out in the event of an emergency.
Traditional photography is unimaginable without the use of chemical solutions. In a crowded world it is important to keep hazardous chemicals separate from the environment. Therefore, during recent years, around the world environmental legislation as well as workplace health and safety regulations have become more stringent.
Our improved understanding of the impact of individual chemicals on the environment has allowed HARMAN technology Ltd to consistently make improvements to reduce the effects of our products and wastes. This has included the replacement of the chemicals of most concern as well as a reduction in the volume produced by our processes. HARMAN technology Ltd products are famous for the highest quality in all aspects, and this includes workplace and environmental safety.
Photo processing chemistry has not only to be judged in terms of its effects on man through possible exposure in the workplace (see How can photographic chemicals enter and affect your body), but also in terms of its effects on the environment when it becomes waste. The main factor influencing environmental effects is the method of disposal. Clearly, waste chemistry entering a natural waterway can be more harmful to the environment than a solution properly disposed of by a waste handling company. Today responsible photo laboratory owners either treat their waste before disposal or have it hauled away by a licensed waste disposal company. However, wash water from photo processors, which contains very small amounts of photo chemicals carried over from the processing tanks, can usually be discharged to the sewer. This must of course be checked with your local utility provider
Chemicals that may enter the sewer have to be judged concerning their biodegradability (ease of being destroyed or broken down in the environment) and toxicity (hazard posed to the environment). Fortunately, most photographic chemicals are non-toxic or easily biodegradable and many therefore pose no problem for the environment. Micro-organisms, growing in waste water treatment facilities or in rivers and lakes easily take care of them.
Some current issues are discussed briefly below.
Silver halide salts are contained in all conventional photographic materials as the active components of the photosensitive system, and the image in B&W images is also composed of silver.
Silver is present in small amounts in used developer and in moderate quantities (3 - 8 g/litre) in used fixer. Therefore some silver gets into the waste from the wash after fixing. Silver from a photographic process leaves the system as a practically non-toxic complex with thiosulphate. The binding of silver to thiosulphate is extremely strong and prevents the release of free silver ions (the toxic form of silver); silver thiosulphate is rapidly transformed in waste water treatment plants into non-toxic silver sulphide. Silver sulphide is very stable and insoluble, so it will not change further and precipitates as sludge.
Hydroquinone is the main active ingredient in most black and white developer solutions. In high concentrations it is dangerous for the environment, and most developers are therefore described as “Very toxic to aquatic organisms” or (following the CLP Regulation) “Very toxic to aquatic life.”
It is important to recognise that the above classification applies to the fresh concentrated developer as supplied: once the developer has been made up and used, its hydroquinone level will be very low. In most cases hydroquinone levels are already below the detection limit at the entrance to the water purification plant, and any residual hydroquinone will be easily handled by the plant.
Rapid fixers contain ammonium thiosulphate. As the name implies, this a source of ammonium ion. Ammonium ion enters natural waterways by the ton from farming and domestic waste water, (these account for over 80% of the nitrogen added to the environment). It is not toxic and functions as a fertiliser, leading to algae growth in lakes and rivers. However this is an unwanted effect which makes the control of ammonia an environmental concern. Ammonium ion is biodegradable, so if wash water from your processor is delivered to a modern water treatment plant, it will be fully broken down to nitrate and then to nitrogen.
Boric acid and its salts (borates) are used in some HARMAN technology Ltd developers and Hypam fixer as a pH buffer. Boric acid or borate entering a river or a water purification plant partly precipitates as calcium borate. In nature, borates are found in many different minerals. However, it is known, that dissolved borates in high concentration show some toxicity on plants. The borate level in HARMAN technology Ltd working strength chemicals is low and presents no environmental hazard.
In common with all chemical products, HARMAN technology Ltd photographic processing chemicals may be hazardous to health in many different ways. However provided that these are used according to the instructions and common sense working methods and standards of hygiene are observed the risk to health associated with these chemicals will be adequately controlled.
Inhalation or breathing.
Inhalation is the main route by which fumes, dusts, mists, aerosols and gases enter the body, making good ventilation a high priority. Exposure to irritant chemicals that would not affect most people may provoke an asthma attack in a person who already has asthma. For example, low levels of the gas sulphur dioxide can be produced by some HARMAN technology Ltd processes. Most individuals would be unaffected but asthmatics may need greater ventilation to avoid adverse affects.
Swallowing or ingestion.
Ingestion is normally only a problem when someone eats, drinks or smokes in the laboratory or darkroom. Therefore, take all possible measures to avoid contaminating food or drink with chemicals. Do not store photochemicals with foodstuffs or in containers previously used for storing foods or that look like they contain food or drink. Also make sure containers are correctly labelled to show their contents.
All ILFORD PHOTO liquid photochemicals likely to be used by home users (in bottles holding 1 litre or less) are supplied with child-resistant caps, to reduce the risk of accidental exposure.
DO NOT EAT, DRINK, OR SMOKE IN THE LABORATORY OR DARKROOM.
Personal hygiene is also important because hands can transfer chemicals to foods or cigarettes. If you accidentally swallow a small quantity of a working strength processing solution, do not panic, simply take the first aid measures described in the safety data sheet or on the product label. Always keep all chemicals - household, garden, or photographic - out of the reach of children.
In the case of accidental ingestion, immediately spit out whatever may be in the mouth, and wash out the mouth with water. If any of the chemical was swallowed, it is not recommended to induce vomiting, especially in the case of ingestion of acids or alkalis. They would be corrosive twice; going down and coming up again. Milk should not be considered as an antidote because it may dissolve chemicals which are otherwise insoluble in water and make them available for the body which can actually increase the harm they cause to the body.
The eye is a very sensitive organ and chemicals can very easily enter the eye from splashes. Some HARMAN technology Ltd products (as supplied) are classified “Irritating to eyes” or more seriously “Risk of serious damage to eyes”. Always read the label before using chemicals, so that you know where such risks exist.
If chemicals that are irritating or damaging to the eyes are used and the eyes are splashed, immediately rinse the eyes with running water for several minutes, keep rinsing if discomfort continues, and consult your local doctor or hospital straight away.
Eyes are easily protected by wearing safety glasses. This simple precaution is very effective in preventing eye damage.
Some chemicals can be absorbed through the skin. Unprotected hands should therefore not be immersed in processing solutions – wear suitable gloves, or use tongs. This is good darkroom practice in any case, to avoid getting fingerprints (or worse, photographic solutions) on your images.
How Photographic Chemicals can Affect Your Body
There is no easy way to predict what affect any given chemical of relatively low toxicity, like most of those used in photo-processing, will have on an individual. Everyone responds to chemicals differently, based on the following factors:
- The physical state of the chemical. Air-borne chemicals are more easily inhaled and absorbed into the body than the same chemical in a solid or liquid form.
- The route of exposure to the chemical. Entry into the body via the lungs is a more direct path than through the skin.
- Individual susceptibility. People will react differently to a given chemical substance.
- The work environment. Adequate ventilation ensures minimal exposure to fumes and dusts, and good housekeeping reduces accidental contact.
- The time of exposure of the chemical substance. Generally, increased exposure results in increased risk.
- The amount of chemical the individual has been exposed to.
It is usual to distinguish between those effects of chemical exposure that are categorised as acute effects and those which are chronic effects. There is no hard boundary for the division. Generally acute effects are those which are immediately apparent and occur within a short period (hours or days) of exposure and are often reversible when the exposure is removed; while chronic effects are those that may only become apparent after repeated low level exposure (over months or years) and these may not be reversible.
Some chemicals can cause irritation when absorbed through the skin. Symptoms of skin irritation include dryness, flaking, and cracking of the skin. Skin irritation is an acute effect and can be largely prevented using hand creams and protective gloves.
Chemicals can also cause irritation when inhaled into the lungs. Examples include sulphur dioxide gas, which may be released in small quantities during processing, and dust from powder developers, which could be released during solution making. The main way to reduce exposure by inhalation is by ensuring adequate ventilation.
Some photochemical solutions contain strong acids (eg acetic acid) or alkalis (eg sodium hydroxide). However, no current HARMAN technology Ltd product has a high enough concentration of acid or alkali to be classified as “Corrosive” to its users. HARMAN products will not cause chemical burns.
An individual using a chemical may become sensitised by repeated contact with it. Subsequently, even a tiny amount may cause an allergic reaction. Hydroquinone and Metol (full chemical name bis(4-hydroxy-N-methylanilinium) sulphate) are considered to be sensitisers, although the effect is seen in very few cases.
A doctor may be able to identify if an effect is a skin irritation or a true allergic reaction. It is important to determine the cause of irritated skin conditions as there are many causes other than photographic chemicals. It may help your doctor if, before visiting him, you make a list of chemical products you handled at home and at work over the few days before the symptoms appeared (include such products as washing powders, household bleaches, dishwasher cleaners and gardening chemicals).
The toxicity of a chemical should be viewed in terms of both its acute and chronic effects. Acute toxicity is the risk of harm arising from short term exposure, indicated on labels through the use of the words ‘Toxic’ and ‘Harmful’.
Most HARMAN technology Ltd developers are classified as Harmful. HARMAN Toner Selenium is classified as Toxic. Selenium compounds in general are poisons, and it is especially important to avoid exposure.
Chronic toxicity is the risk of harm arising in the long term, usually from repeated exposure. The long term consequences of exposure to some chemicals can include impaired fertility, irreversible birth defects or cancer. A great deal of attention is therefore given to what is now termed the CMR status of chemicals, ie whether they are carcinogenic, mutagenic or toxic for reproduction.
No HARMAN technology Ltd products use any substances which are known to cause cancer in humans. For some chemicals (eg hydroquinone) there is some evidence of these effects in animals, without a clear indication of harm to humans. Where this is the case, details should be found on relevant safety data sheets.
Some HARMAN technology Ltd products contain boric acid or borates, which are classified as toxic for reproduction. In most cases the boron levels in the products as sold (and in all cases the levels in the products when made up for use) are below those which would be classified as toxic for reproduction. Again, details should be found on relevant safety data sheets.
Other Physical Hazards
As well as their possible effects on health, some chemicals can present other physical dangers to users: they may be oxidising substances, or flammable, or explosive. No HARMAN technology Ltd photographic chemical product presents this sort of danger.
Protective clothing and good ventilation are the most effective ways to ensure safe handling of chemicals.
Wear chemical splash goggles, safety glasses or a visor when working directly with solid or liquid chemicals. An eye wash station should be available in the work room. This could simply be a container filled with fresh or sterile water.
When handling chemicals use gloves whenever possible. Tongs can be used instead of your fingers or hands to agitate solutions or transfer prints or negatives. If hands must be immersed in processing solutions (eg when draining, cleaning and refilling processing equipment), wear protective gloves of special materials such as neoprene, latex/neoprene, or butyl rubber, especially when the product is labelled harmful. Always rinse the gloves with water after contact with chemicals. If you wash your hands frequently, a barrier cream may be useful in preventing the skin becoming dry and flaky.
If extraction systems cannot sufficiently reduce levels of chemical fumes and dusts in workroom air then further protection must be used. When handling powdered chemicals we recommend the use of a dust mask. If large quantities of liquid chemistry are spilled, especially if several kinds are mixed together, complete breathing apparatus may be needed.
All darkrooms or processing rooms need some kind of forced ventilation. This could simply be a fan mounted through an outside wall or it could be a special ventilation system for a machine or a room depending on circumstances. However, processing rooms vary widely in size and in the types of chemicals used in them. Therefore recommendations for ventilation can only be rough guidelines. In general, 10-15 air changes per hour will produce a safe working environment.
The best way to avoid having problems with any chemical products is to keep in mind certain important rules for handling chemicals safely and carefully. Here are some safe working practices that should be followed when working with photographic chemicals.
- Read the Material Safety Data Sheet (MSDS) and Product Label for each chemical in your process, when working with it for the first time.
- Wear safety glasses and gloves when handling and mixing chemicals.
- Use tongs to agitate solutions and transfer prints and negatives between open dishes and tanks.
- Identify incompatible chemicals from information on MSDSs, for example which ones may release fumes when mixed. Do not mix acids with developers or fixers - sulphur dioxide gas will be given off which can be dangerous, especially for asthmatics.
- Dispose of chemicals carefully. Chemicals poured down the drain can react to form dangerous gases. Flushing the drain with plenty of running water will remove this hazard. Most photographic chemicals must be disposed of as hazardous wastes. It is often illegal to pour them down the drain or discard them with ordinary waste water. Consult your local waste authority for further advice.
- Do not eat, drink or smoke in any area where chemicals are handled, stored, or used.
- Wash your hands after using chemicals.
- If you spill a chemical, on the floor or inside the processor, clean it up as soon as you can.
- Keep the work area clean and tidy.
- Mixing of working solution chemistry from bulk chemicals may require additional protective clothing such as gloves and safety glasses, that may not be necessary when using the working-strength solutions.
Pregnancy should not be equated with ill-health but treated as a part of everyday life. The health and safety of pregnant women can be protected adequately by applying existing health and safety management procedures in the relevant areas.
Many women work while they are pregnant and many return to work while they are still breast-feeding. However, some hazards in the workplace may affect the health and safety of new and expectant mothers, and conditions otherwise considered acceptable in work situations may no longer be so during pregnancy. A risk assessment should therefore be undertaken which considers the likelihood of any potential hazard that may be present to cause harm, and identifies any changes to working practices or conditions that may be required. Although these notes are about potential risks from exposure to photochemicals, it should be recognised that other risks may need to be avoided, such as repeated or heavy lifting, or working at height or in tight situations.
With specific reference to chemical agents and pregnancy or breast-feeding, those with risk phrases which refer to cancer, genetic damage, harm to the unborn child, or harm to breastfed babies require appropriate controls to be in place to control risk.
ILFORD PHOTO products include no known human carcinogens, and no substances to which phrase R46 - May cause heritable genetic damage or R64 - May cause harm to breastfed babies applies.
Most ILFORD PHOTO developers use hydroquinone, and their classification therefore includes
R40 - Limited evidence of a carcinogenic effect and R68 - Possible risk of irreversible effects.
Some ILFORD PHOTO chemicals use boric acid or borates. These substances are classified as toxic for reproduction. As a result, the classification of some of the powder developers includes R60 - May impair fertility and R61 - May cause harm to the unborn child.
The product label and the safety data sheet will indicate the hazards and risk phrases. From a risk assessment standpoint, provided all necessary control measures (such as good working practices, adequate ventilation, and the use of appropriate PPE) are in place then pregnant and breastfeeding women should be able to continue to work safely with photochemical products.
Hydroquinone was discovered in 1880 and has been used in ILFORD photographic chemical products for over 100 years. It is the main photographic developing agent for most black and white processes and is used throughout the photographic industry.
Other current uses include:
- as an antioxidant in the manufacture of rubber
- as a polymerisation inhibitor in the chemical industry.
Hydroquinone, or arbutin, from which it is released by the digestive process, occurs naturally in a number of foods and drinks:
- whole wheat products (e.g. bread and cereals)
- fruits (eg pears and blueberries/bilberries) and vegetables (e.g. broccoli and asparagus)
- coffee and tea
- some beers
- red wine.
Only 2 definite human hazards have been identified:
- skin irritation, with possible risk of sensitisation – which is why it is no longer allowed to be used in skin whitening creams or other cosmetics in the EU
- eye irritation and discoloration, with possible impaired vision in cases of extreme exposure (high levels of hydroquinone dust over several years).
Hydroquinone environmental facts:
- it has a low vapour pressure and reasonable solubility in water, so it does not readily evaporate into the air from working solutions or process wastes
- it biodegrades in sewage treatment processes - bacteria, yeasts and fungi in soils and sewage sludges can all use hydroquinone as a source of carbon
- it is very toxic to fish, etc.
The hazard classification of hydroquinone has been agreed at European level. This classification is reflected in HARMAN technology Ltd product labelling and safety data sheets.
The current EU harmonised classification for hydroquinone as a pure substance is:
Carcinogen 2: H351 - Suspected of causing cancer
Mutagen 2: H341 - Suspected of causing genetic defects .
Acute Toxicity 4 *: H302 - Harmful if swallowed.
Eye Damage 1: H318 - Causes serious eye damage.
Skin Sensitiser 1: H317 - May cause an allergic skin reaction.
Aquatic Acute 1: H400 - Very toxic to aquatic life.
The equivalent older classification, which is still applied to hydroquinone when it is included in chemical mixtures such as photographic developers, is:
Carcinogen 3: R40 - Limited evidence of a carcinogenic effect
Mutagen 3: R68 - Possible risk of irreversible effects
Harmful: R22 - Harmful if swallowed
Irritant: R41 - Risk of serious damage to eyes
R43 - May cause sensitisation by skin contact
Dangerous for the Environment: R50 - Very toxic to aquatic organisms
This classification as a possible or suspected carcinogen and mutagen is based on some evidence of cancer in animals only and on some evidence of damage to genetic material in animals only. There has been an inconclusive debate for many years about the long term effects of human exposure to hydroquinone. There is no evidence, despite over 100 years of use, that any person has ever developed a cancer that can be categorically linked with exposure to hydroquinone. Indeed, in some human studies of workers handling hydroquinone regularly (during the manufacture of photographic chemical products or use in photographic processing laboratories) the rate of cancer was slightly lower than for the general population.
On the other hand, the classification of most hydroquinone-based developers now includes the risk phrases “Limited evidence of a carcinogenic effect “ and "Possible risk of irreversible effects". In view of the previous paragraph, this may appear to be over-cautious, but it reflects the latest improvements in awareness around the health and safety of chemicals, and appropriate steps should be taken to minimise contact with hydroquinone.
Absorption through human skin is slow, so liquids pose a low risk, especially since wearing protective gloves prevents skin contact.
Powder products, which can become airborne and be breathed into the body directly, are a greater risk. Good ventilation is essential when handling powders. Dust masks are required and breathing apparatus may be necessary if the dust becomes airborne during mixing.
Sulphur dioxide (SO2) is quite a common gas:
- it is used as a preservative in foods and wines
- it is produced in small quantities when you light a match.
- it results from the burning of coal, oil, vehicle fuel, etc.
- it also responsible for acid rain.
In the USA it is estimated that 500,000 workers are potentially exposed to sulphur dioxide, encountered in many industrial processes, from the manufacture of steel and bricks for buildings to chemical plants.
Small quantities of sulphur dioxide may be produced when processing black and white materials. As material is passed from the developer into an acid stop bath, traces of sulphite carried over may react to give sulphur dioxide gas.
This sulphur dioxide is very soluble in water and processing solutions, so it is mostly absorbed by the processing bath, as well as by the standard exhaust filters of processing machines. Properly maintained processing machines in well ventilated rooms will produce a levels of sulphur dioxide below the level at which it becomes a hazard or affects the user.
If you accidentally mix an acid with developer or fixer, larger amounts of sulphur dioxide will be generated:
- Leave the room immediately and go out into the fresh air
- Wait until no more gas is formed, then open windows and doors to flush fresh air into the room
- Dispose of the mixed solutions carefully
- Use a licensed waste disposal company if local regulations prevent discharge of waste to the drains
- Recent evidence has shown that much lower levels of sulphur dioxide than previously thought to be of concern can affect asthmatics. If problems do arise then further ventilation and extraction should be installed. In extreme cases it may be necessary to move the person affected away from this work area
The primary means of communicating information about the hazards of any product is through the product label and packaging. When a product may be harmful, HARMAN technology Ltd prints a warning on the label of the bottle or pack. The process for determining and communicating chemical hazard information is internationally regulated and we go to great lengths to ensure that our products meet regulatory requirements.
Always read the label before using any chemical product for the first time.
The secondary means of communicating chemical hazard (and other) information is through the (Material) Safety Data Sheet (MSDS or just SDS). Manufacturers of hazardous preparations are required to produce and make freely available MSDSs for each of those products. HARMAN technology Ltd produces MSDSs for all of their chemical range (regardless of hazard or need) and all of these are freely available for download from this web site.
Global Harmonisation For Supply (GHS)
GHS is a new set of regulations being adopted worldwide that will affect the labelling of many chemical products, including HARMAN technology Ltd photochemical solutions. We will also have to change and update our Material Safety Data Sheets.
In Europe, GHS is represented by the European CLP Regulation 1272/2008 and in the US by Hazcom 2012 Standard, and there are equivalent regulations in other countries. In order to complete the lengthy process of relabelling most of our photochemical product range to accord with GHS by the deadline of 1st June 2015 we will gradually be introducing products with the new labels starting in July 2014 and making the relevant new MSDSs available at the same time. (Products labelled the old way that are already in the supply chain will still be in use for some time after that.)
We should emphasise that the changes only affect the way hazard information is generated and communicated, and that there are no changes to the formulations of the products themselves.
A typical OLD-STYLE (European) label on a HARMAN technology Ltd product may contain:
- one or more graphic or symbolic warnings of danger shown on a square orange background (eg a black X)
- a warning word: eg harmful, or irritant
- risk statements (R-phrases): eg irritating to skin and eyes
- safety statements (S-phrases): eg If swallowed, seek medical advice immediately and show this container or label.
On the NEW-STYLE labels the same information is presented somewhat differently:
- one or more GHS pictograms, each in black on white and enclosed in a red diamond border: in some cases the actual symbol remains the same, but other new symbols are also used (eg a black exclamation mark)
- a “signal word”, which is always either WARNING or DANGER
- Hazard statements (H-statements, replacing the previous R phrases): eg causes skin irritation; causes serious eye irritation
- Precautionary statements (P-statements, replacing the previous S-phrases): eg If swallowed, immediately call a Poison Centre or doctor/physician.
Note that while some GHS pictograms indicate the existence of health hazards, it is essential to read the H-statements to determine what those health hazards are.
Where applicable, the label will identify the ingredient(s) that give rise to the key hazardous properties of a preparation – eg hydroquinone for most developers.
The labelling changes will not affect our existing practice of incorporating:
- a tactile warning (an embossed or raised triangle) on bottles and cartons of harmful products that may be used in the home;
- childproof caps for the smaller bottles of all our products.
HARMAN technology Ltd Safety data sheets (MSDSs or SDSs) provide detailed information to assist our customers in identifying the hazards and ensuring safe storage, use and disposal of our formulated products.
For a period, we will be making two sets of MSDSs available on our website; those covering products still in use with the old labels and those for products relabelled under the new GHS system. To avoid confusion, the new versions are identified by the suffix GHS in the listing.
MSDSs are presented in the 16 section format that is required under the European REACH Regulation and the US Hazcom 2012 Standard.
Through the MSDS, we attempt to provide all the essential facts relating to safe practice. However, these may still not contain all of the details you are looking for. If you require further information on any aspect of safety relating to the use of photographic chemicals, please refer to other HARMAN technology Ltd web site HS&E pages or contact, during working hours, the distributor or sales office nearest to you.
MSDSs are produced for every HARMAN technology Ltd photochemical product, including those products that are not classified as hazardous under EU and US rules.
These MSDSs are for the products in the form in which they are sold. They are produced in 11 different European languages - English, Spanish, Danish, German, French, Italian, Dutch, Portuguese, Finnish, Swedish and Norwegian - plus a US English version.
For the convenience of our customers “working strength” MSDSs are also produced, in English only, for the photochemical products when made up as stock solutions or to a recommended working strength. These are for guidance only, as HARMAN technology Ltd has no control over the actual concentrations used, and there is no legal requirement to provide them.
Finally, MSDSs are produced for HARMAN’s Nuclear Emulsions, which are used in some specialised scientific research.
All of these MSDSs are freely available from ‘Safety Data Sheets’ pages of the HARMAN technology Ltd web site.
MSDSs are not produced for photographic film or paper, or for any other products which are considered to be ‘articles’ and as such do not need an MSDS. Health and safety information applicable to these products is included in their technical data sheets.
All HARMAN technology Ltd MSDSs have 16 sections. Brief explanations of some of the sections are given below.
This section contains basic information to identify the preparation and the supplier and a contact address for further information in the event of an emergency.
Wherever possible the name and address of the local supplier/distributor has been given. In some cases, especially for an MSDS in a language that is used in several countries, several distributors may be identified (eg the French language MSDS is used in France, Belgium, Switzerland, and Canada).
Where the facilities exist, a 24-hour emergency telephone number is provided.
In an emergency (for example, if a chemical has been accidentally swallowed) you should go to your doctor or your local hospital. Make sure you take the bottle of photographic chemical with you to show the doctor the health and safety information on the label. Take the MSDS along as well, if you have one. The doctor should be able to obtain further toxicological details on the product concerned from a poison information centre; most countries now have a national poison information centre.
This section identifies the hazards associated with the product, and states its formal hazard classification.
To do this, it uses fixed terminology from relevant legislation.
In the older MSDSs on the website, the wording is based on the Dangerous Preparations Directive (1999/45/EC). In the newer MSDSs, whose titles in the listing include “GHS”, the terminology of the CLP Regulation is used.
The hazards associated with each product are calculated from those of its individual constituents, using methods set out in the relevant legislation.
This section identifies ingredients in the preparation. It does not normally give a complete breakdown of any product.
In all cases it identifies constituents that are required to be notified because they have official exposure limits (see under Section 8).
In the older MSDSs it lists the constituents that contribute to the overall hazard classification of the preparation.
In the newer MSDSs (labelled “GHS” in the listing) it lists the constituents that contribute to the classification in relation to key hazards specified in the CLP Regulation.
The substances listed in this section are identified by a recognisable chemical name, and also by the CAS-No which is the Chemical Abstracts Service Registry Number - a unique number assigned to individual chemicals that is used and recognised world wide. In addition, chemicals are identified by the EC No which is the number on the EU register.
All chemicals used by HARMAN technology Ltd are registered on TSCA (USA), the DSL (Canada) and EINECS/ELINCS (Europe).
WEL - Workplace Exposure Limits are limits for the concentration of chemicals in the working atmosphere. The concerns here are with dusts and volatile chemicals. Where exposure limits are set, these are either quoted as short term (15min), long term (8hrs) or maximum values.
Other countries have their own systems of exposure limits, with different names; relevant values, with the appropriate terminology, are included in MSDSs in other languages.
This section contains information about the toxicity of the chemicals that were used to make the preparation, to humans and to other mammals.
HARMAN chemical formulations have not themselves been tested; the details in this section are the known toxicological properties of the individual ingredients, normally obtained from their suppliers.
LD50 - result of acute toxicity tests on animals (generally values for rats, since these are the most widely available data). A figure of less than 2000 mg/kg is considered to be hazardous. The lower the number, the more hazardous the chemical.
This section contains information about the environmental toxicity of the chemicals that were used to make the preparation.
LC50 - results of acute toxicity tests on fish.
IC50 - Immobilisation concentration of daphnia - toxicity data for aquatic life
This section gives information about the classification of the product for transport purposes.
Products may be classified as hazardous for transport purposes for many reasons, and there are many similarities with the chemical hazard classification covered by Section 2. In addition, a product may be classified as corrosive for transport purposes (based on its effects on steel and aluminium) without being classified as corrosive in Section 2.
ADR – European regulation on carriage of dangerous goods by road.
IATA AND ICAO - The organisations and regulations that control the carriage of dangerous goods by air
IMDG - International maritime dangerous goods code for transport by sea
RID - International carriage of dangerous goods by rail
UN No - United Nations transport code number (used world-wide). These are assigned to single chemicals or groups of chemicals. They are therefore not necessarily unique to a particular substance.
ILFORD PHOTO black and white photographic films and papers are articles. They are not subject to the legislation that regulates the supply of dangerous substances and preparations, and Safety Data Sheets (MSDSs/SDSs) are not required. None of these products is classified as hazardous for transportation (by any means).
However, HARMAN technology Ltd recognises that information such as that which would be expected to be found in a typical Safety Data Sheet may be desired by customers. These following sections present some of this information, about composition, toxicity, fire hazards, etc.
ILFORD PHOTO film and papers are produced by aqueous coating onto various types of film and paper base (opaque or transparent).
Camera films in 35mm and 120 formats are coated onto cellulose triacetate. Sheet and other film formats are coated onto polyester (PET). All HARMAN film bases comply with ISO 543:1990.
Black and white papers use either baryta (FB) or polyethylene resin coated paper (RC) base.
The bases are coated with thin layers of light-sensitive silver halide dispersed in aqueous gelatin. The base typically comprises 80% to 90% by weight of the total.
HARMAN technology Ltd’s coated film and paper products have not been tested for toxicity. However, on the basis of what we know about what goes into them and how they are made, together with information that has been published within the imaging industry about similar products, we have no reason to believe that any of our films or papers (either processed or unprocessed) has a significant acute toxicity.
In all cases except one, the products do not represent any hazard that is significantly different from the properties of the film or paper base upon which they are coated.
The exception is XP2 Super film, which contains some dibutyl phthalate. This is now designated a Substance of Very High Concern in the EU, it is classified as Toxic for Reproduction, and its use is being phased out across the EU. XP2 Super film (processed or unprocessed) should be kept out of the reach of children. It should not be placed in the mouth, and if handled for extended periods of time, gloves should be worn. In this one case, processing laboratories should treat scrap film as hazardous waste.
(To put this into context, dibutyl phthalate was used very extensively in the past as a plasticiser in flexible plastics such as PVC, and in inks and sealants. It is present in many everyday items, including (eg) vinyl flooring, injection-moulded shoe soles, shower curtains, and electrical cables.)
The purpose of this and the following sections is to provide information to guide customers who have specific performance criteria that must be met, to make a product choice that best meets their requirements, and also to provide information to those customers who may have specific information requirements.
The combustibility of ILFORD PHOTO products is considered in general terms. The topic of fire classification and how it relates to these products is discussed, and the burning characteristics of the products are described.
Most of the information applies to the entire ILFORD PHOTO product range; there are no specific data relating to individual products. For information about individual products, refer to the product technical information / specification.
Under normal conditions, no ILFORD PHOTO product is considered to be flammable – i.e. they are not inherently capable of producing a flame, either spontaneously, or with a low energy initiator such as a spark.
On the other hand, all ILFORD PHOTO films and papers are combustible - i.e. they will burn when exposed to a sufficient flame and may continue to burn when the initiating flame is removed. Under extreme conditions of very high temperature and when initiated by a direct source of heat (such as may exist in an existing fire), a product will char and may develop a flame.
Thus no ILFORD PHOTO film or paper is considered to be capable of starting a fire, but they will all be damaged by fire; and when subjected to the conditions within a fire they will all (to a variable extent) sustain or propagate the flame.
The measurement of this variable capacity to sustain or propagate a flame is called 'Fire Classification'.
Largely driven by the need to ensure that 'safe' materials are used in the building construction industry, and developed and approved independently by many different national standards organisations, there are many different test methods which can lead to a classification for the burning characteristics of different materials. There are also regulations which specify what types of materials (or that materials with specific burning characteristics) may be used in different applications.
Except for ANSI/ISO 543:1990 which was developed by the photo industry and details test protocols and specifications for the base materials which have to be met in order for predominantly silver halide materials to be classed as 'safety film', there are no standards which explicitly address the issue of classification of the burning characteristics of imaging/display media. The choice of test protocols and the classification of these products can be a complex process. (Further complicated by the fact that the US, Canada, Australia and all the Western European states have their own (different) test methods and standards).
Within the European Union there has been a harmonisation of test protocols. This has been achieved during the implementation of the Construction Products Directive (89/106/EEC) and this has also given rise to new combustibility and burning characterisation test methods. Among these there are tests which are clearly more appropriate for testing display media.
The new, harmonised (EU) classification set out in EN 13501-1 adopts a single Euro classification scale ranging from A indicating non-combustible through G, indicating rapid burning to F indicating not-tested. This is based upon testing in the most appropriate of several new test protocols, among which the one which is most appropriate for these media is EN ISO 11925-2.
EN ISO 11925-2 is a test of ignitability when subject to direct impingement of a small flame for a fixed period of time to a vertically mounted sample. It includes a measure of the likelihood of any burning drops that fall from the material to spread a fire.
Euro classification is now accepted throughout the EU and is now the most appropriate route for testing these media. Euro classification is an alternative to those diverse national tests described for example, in the UK in standards such as BS 476:1997 and BS 5438 & BS 5867 (the standard for the classification of building materials, and standards for fire resistance of textiles and fabrics; and in France, in NF P 92501-7 (the standard for evaluating the burning behaviour of fabrics which gives rise to the M0-M5, classifications)
No ILFORD PHOTO product is constructed from materials which are inert to fire, and thus no product is expected to be classified 'non-combustible' (A) in the Euro classification.
ILFORD PHOTO products have not generally been tested to EN ISO 11925-2, so their current classification under EN 13501-1is generally Euro classification F (not tested).
For ILFORD PHOTO films, which are coated on triacetate or polyester base, the base meets the requirements of ANSI/ISO 543:1990 for classification of the product as 'Safety Film'. This means that these are difficult to ignite (after being kept for more than 10 minutes at 300°C), they are slow burning (a 0.08mm thick and 300mm long sample burns for more than 45 seconds), and they contain less than 0.4% nitrogen.
Consideration of the materials used in the production of the products and a knowledge of their known or expected burning characteristics leads us to conclude that if they were tested, all of the films and papers would fall into the Euro classification combustible classes B, C, D or E.
If an ILFORD PHOTO film or paper product is burned in a hot fire with plenty of oxygen (e.g. in an incinerator), it will be consumed to produce (primarily) water and carbon dioxide, together with small amounts of nitrogen oxides, and ash which will contain some silver. Ash from a paper product will also contain either titanium dioxide or barium sulphate. Under these conditions no harmful substances are produced during combustion.
In a cooler fire, with insufficient oxygen with consequent incomplete combustion, all products will burn slowly and produce a noxious smoke.
The burning characteristics of film or paper are largely those of the substrate base material, but this is influenced by the presence of the coated layers that are introduced during their conversion into imaging materials, and by any processes that are subsequently used to reveal, modify or stabilise the image. The burning characteristics of the different bases used are:
Products Coated on Triacetate Base
Most ILFORD PHOTO films comprise a thin layer of silver halide dispersed in gelatin, coated onto cellulose triacetate base. Cellulose triacetate meets the requirements of ANSI/ISO 543:1990. It starts to melt at 230°C. In a fire the melting behaviour of triacetate base is a significant factor. Unless these products are mounted onto a rigid and inert support, then they tend to melt away from a flame and this invalidates the application of many of the older fire test protocols. Once it is alight, triacetate can burn vigorously and drop flaming droplets. The coatings applied in the manufacture of photographic products based on triacetate do not significantly affect the burning behaviour of the base, but may contribute to the production of a greater diversity of noxious gases during incomplete combustion.
Products Coated on Polyester Base
A small number of ILFORD PHOTO films are coated onto polyester (PET). PET (polyethylene terephthalate) starts to melt at 255-260°C (at which temperature it starts to decompose) and has a flash point of 440°C. In a fire the softening and melting behaviour of the polyester base is a significant factor. Unless these products are mounted onto a rigid and inert support, then they tend to melt away from a flame and this invalidates the application of many of the older fire test protocols. Once it is alight, PET can burn vigorously and drop flaming droplets. The coatings applied in the manufacture of photographic products based on PET do not significantly effect the burning behaviour, but may contribute to the production of a greater diversity of noxious gases during incomplete combustion. In general, polyester films are slower burning than triacetate. In a flame spread test the rate of flame spread along a 25.4 mm wide strip of 0.05mm thick PET base was 250-300 mm/min.
Products Coated on Paper Base
ILFORD PHOTO photographic papers are coated on paper base, either resin coated or baryta coated. Paper is easily ignited - the ignition temperature is about 230°C. The burning characteristics of paper are strongly influenced by the paper thickness (thin papers burn faster). The burning characteristics of photographic papers coated with a thin layer of silver halide dispersed in gelatin are not significantly different to the uncoated base. In general, resin coated papers (which have a thin surface coating of polythene, usually on both sides, to impart robustness and water resistance) are slower burning than papers without the resin coating.
Mounting and Lamination
If imaging media are mounted onto boards for display purposes, framed behind glass, lacquered for surface protection, laminated etc., the effect of these additional processes on the burning characteristics of the image will need to be considered.
If you have large quantities of ILFORD PHOTO films and papers to dispose of, you should investigate recycling and silver recovery options, for both environmental and cost reasons.
Where applicable, ILFORD PHOTO films and papers should be disposed of in accordance with any specific local regulations. Scrap XP2 Super film should be treated as hazardous waste.
ILFORD PHOTO films and papers should not generally be considered as hazardous, and when they become waste they can be disposed of safely by incineration.
Today, photographic processing technology and environmental care are inseparable. Treatment of waste effluents from processing has become an important issue in good laboratory practice. There are a wide variety of waste treatment systems.
Waste volumes differ between sources. Amateur and home users in the UK should dispose of small amounts of used photographic processing solutions by dilution with plenty of water and washing them down the drain. Do not mix solutions. It is not advisable to dispose of photographic chemicals to a septic tank.
Larger users, professional and commercial operations operate under fast changing and often local legislation. Many authorities prohibit disposal of used chemistry to the sewer. It is usually unacceptable for economic and environmental reasons to dispose of used tank solutions as waste water. This has led to many developments aimed at minimising waste. Tank solutions now use lower concentrations of chemistry and lower replenishment rates. Fixer desilvering which used to be justified solely on the value of the silver collected now also has the additional justification of lowering the levels of silver in waste to avoid punitive pollution charges and fines. Other processing solutions can easily be collected, neutralised and treated by a specialised contractor. Waste handling companies offer collection schemes which guarantee environmentally sound treatment of photochemical waste. Furthermore, your laboratory has different options to reduce the amount of waste - and as a result to reduce costs. The kind of additional treatment that is appropriate will of course depend on your special situation, but these include:
- Separate collection of tank overflow: Developer and fixer overflow have to be collected separately to allow further treatment.
- Fixer overflow contains a moderate amount of silver. Desilvering can either be done by yourself or by a photo waste collector, who will usually refund most of the value of the silver. Many desilvering systems are on the market but not all show the same efficiency. For reasons of economy electrolytic desilvering units are usually the best choice.
- Equipment for reducing volumes of waste solutions: Special equipment is available to reduce waste volumes (evaporation, distillation). Lowering the amount of water yields a smaller amount of more concentrated waste. Before investing in such equipment contact your local waste collector. In many cases a disposal charge is not only based on volume but also on concentration. By concentrating, waste can also become more hazardous and consequently more expensive to dispose of.
- Wash water: Depending on local legislation disposal to the drain may be allowed or restricted to a maximum volume or concentration. From the fixing solution a small amount of silver is transported into wash water. Desilvering is possible using a metal exchange (iron) cartridge or an ion exchange column.
The substances present in effluent generated by the processing of photographic materials vary according to the processes involved. It is therefore important that the user monitors the waste and reduces levels of hazardous components by pre-treatment in order to meet with local regulations. Care should be taken to ensure that no effluent generated from photographic chemical waste is allowed to enter open streams, watercourses or lakes without suitable treatment and approval from the local Utility service provider.
HARMAN technology Ltd does not recommend the disposal of photographic wastes using septic tank systems because this can affect their efficient operation. Septic tank systems are generally designed for domestic waste treatment in rural areas where mains drainage is not available. While they can and do cope with small quantities of household chemicals, it is best to avoid adding photographic chemicals to them. It should also be borne in mind that the liquid run-off from a septic tank could carry contaminants into the environment.
However, it does depend on the size, design, sitting of the system and sensitivity of the local environment, as well as the volume of photo waste compared to other wastes going through the system. In all cases of doubt, seek expert advice. Alternative waste disposal options for darkroom workers whose property is connected to septic tank systems include:
- Using a licensed waste disposal company
- Contacting your local public (municipal) waste company. These sometimes operate their own waste collection and disposal services.
The oxygen demand (COD, BOD) of an effluent is determined by its chemical content and the degradability of its components. A high COD (chemical oxygen demand) or BOD (biological oxygen demand) value means a high concentration of chemicals. Used tank solutions contain a high concentration of biodegradable chemicals and therefore have high COD and BOD values. Because of a possible impact on the environment through removal of oxygen, they are not recommended for disposal directly to drains. Photographic wash water CODs are low enough to be safely handled by your water treatment plant.
In many areas photo labs need a permit to discharge to sewers. It is important that water treatment plants know what quantities of chemicals are present in waste and from what kind of users they have been produced. Applying for a permit to discharge helps the water treatment plant to run its process in optimal conditions. Contact your Local Trade Effluent Regulator to see if a permit is required.
The recovery of silver should be considered essential by professional users, not only from an environmental point of view but also to avoid loss of a valuable resource.
Fortunately, it is easy to recover silver from used fixer solutions and from fix/wash solutions. Several methods are known, and equipment is commercially available for recovering silver from waste photographic solutions; three of these methods are covered below.
Metal exchange is the cheapest form of silver recovery available, and is suited to the small volume users on a tight budget.
The method involves exchange of metal, usually iron in the form of steel wool, with silver releasing the iron into the wash water. Steel wool however is not very efficient because over a period of time it breaks down, collapses and the silver deposited becomes a sludge. The wash water also appears brown from the waste iron produced, which is not only unsightly but is also restricted in some areas. Several manufacturers market cartridges or drums packed with steel wool for silver recovery. HARMAN technology Ltd testing has found this method to be very successful at keeping silver levels at around 20ppm, but not below 5ppm on a reliable basis Cartridges containing finely-divided iron are the most efficient. If two of these are used one after another it should be possible to reach silver levels under 5ppm. For black and white processes it is an inefficient method for wash water alone - the steel wool rapidly rusts - but for waste containing fixer (which prevents the steel wool from rusting) it works well.
This method is more expensive than metal exchange. It is only used for removing low concentrations of silver from waste, eg from wash water; fix waste is too concentrated in silver for this method to be used.
The ion exchange system, suitable for all sizes of business, involves passing wash water through a bed of ion exchange resin to enable the silver to exchange sites with the resin. The resin needs to be regenerated after prolonged use to prepare the ion-exchange sites for further silver recovery.
Once the resin has become saturated with silver it must be sent to a refinery for silver recovery. Commercial units claim to desilver down to 0.5ppm.
This can be the most efficient method and is less expensive than ion exchange. Some commercial units can remove silver from waste fixer and from combined fix/wash water from a level of 6.5g/l silver down to 3ppm (meeting the silver limit in many parts of the world). However, many units would be unable to decrease silver levels below 50ppm. Ion exchange or metal exchange of the liquid residue from the unit would then be needed to reduce the silver to an acceptable level.
The method involves electroplating silver onto a cathode, usually made of stainless steel. The silver, of up to 98% purity, can be scraped off at intervals. Historically, equipment has not been able to avoid breaking down the fixer (sulphiding) when the silver concentration becomes very low. Breakdown of the fixer leads to silver sulphide being deposited on the cathode which impairs further silver recovery. Hazardous hydrogen sulphide gas (bad eggs smell) can also be given off if electrolysis is too vigorous.
In electrolytic silver recovery systems, two types of electrode may be used, the stationary electrode or the rotating electrode. In a unit employing a stationary electrode, agitation of the solution to enable even desilvering of fixer is achieved by recirculating pumps. Without agitation, a fixer solution would end up with the area nearest the cathode becoming desilvered and the areas furthest away left unelectrolysed. A further disadvantage would be that the solution nearest the cathode would eventually degrade to silver sulphide and hydrogen sulphide.
In units using the rotating electrode, the cathode rotates via a central pivot, causing even desilvering of fixer. In such desilvering units there are moving parts involved which can wear out and this is sometimes seen as a disadvantage.
There are two ways of desilvering fix - either batch wise or continuously (as in recycling).
Batch wise desilvering of exhausted fixer involves vigorous electrolysis to remove as much silver as possible in the shortest possible time without decomposing the fixer.
The use of fixer recycling equipment can give savings on chemicals and waste disposal. Continuous desilvering (in-line desilvering coupled with fixer recycling), involves gentle electrolysis to maintain silver at a constant level without affecting fixer activity. Fixer recycling requires monitoring of thiosulphate and sulphite concentrations because these are affected by electrolysis and will decompose.
Replenishment rates may be reduced by up to 75% by applying recycling when using normal fixers, such as ILFORD 2000RT or HYPAM. If you use recycling you will need to control your processes much more carefully than is otherwise required - it is suggested that you try reducing the replenishment rate by 50% to start with.
Please note that fixer recycling is very dependent on the equipment that is used, the way it is set up and the careful monitoring of the process in order for it to be successful. If not operated properly, film and print stability can be affected. You may not see an effect immediately but your customers may see problems arising after weeks or months.
Hydroquinone (present in virtually all developers for black & white photography decomposes irreversibly with time to form oxidation products, making the scope for developer recycling small. The combination of reduced replenishment rates (which is the aim of all manufacturers) and developer recycling increases the tendency for a brown sludge to form in the processor tank. HARMAN technology Ltd does not recommend the recycling of developers for photographic processing systems.
Wash water is a business cost twice over, particularly if you are on a meter and you have processing machines running continuously. You pay once for water coming into your premises, and again for the waste water leaving your premises. In addition, if you are using heated water the cost of heating can be high.
ILFORD machines typically use water at a rate of 4 litres per minute (240 litres an hour).
Wash water recycling is best suited to the larger user, and has obvious advantages in those countries where effluent disposal is very carefully controlled or restricted. The advantages of this system are:
- Silver recovery by ion exchange of the 10% or more silver lost from photo processing wash water; claims of 90% efficiency are made depending of system used.
- Large quantities of water used for photo processing can be reused, a saving of 66% on mains water consumption (and water plant treatment costs).
- The wash water returning to the processor is at a higher temperature than tap water and can result in energy savings of over 45% by not having to heat up the wash water.
- Elimination of trace quantities of heavy metals, pollutants, and removal of silver down to less than 0.5ppm levels.
Wash water recycling is not suitable for the small user, but as regulatory controls tighten and the need for vigilance over what goes down the drain increases, recycling will become more popular and economic for larger users.
Wash water contains contamination from 2 sources - the film or paper and the fixer tank, which is always before it in the process. The chemicals that are carried over from the fixer are the most important ones for calculations of levels of chemicals in wash water. The chemicals from the film or paper, by this stage in the process, are so small that they can effectively be ignored.
So how much and what is carried over from the fixer tank into the wash tank?
Silver is the main contaminant and the level will depend on a number of things. Throughput (amount of material processed each day) determines the silver load going into the fixer.
The fixer replenishment rate determines the resulting silver level in the fixer tank, in the absence of fixer recycling. If the replenishment rate is halved the silver level in the fixer will double. This in turn means that twice the amount of silver will transfer into the wash water tank. It is important to control the silver level in fixers because if it rises too high it will slow fixing down so much that problems with print or negative stability will result.
An example of the amount of fixer carried over with ILFORD black and white processing machines is between 20 and 40ml for each square metre of paper processed. For ILFORD black and white processing machines a typical silver level in wash water is a few parts per million (ppm).
In actual fact the calculation of silver in the wash tank is not simple. It depends on the water flow rate and the amount of silver that has already been carried into the wash tank. For example, doubling the wash water flow rate will halve the amount of silver in the wash tank.
If 50% wash water recycling is used the silver level will be doubled. Consequently, it may be necessary to ensure that your system is capable of removing some of this silver. For working with such low levels of silver an ion exchange resin system will probably be required. These can reduce the silver level and when the resin cartridge is exhausted the silver can be recovered.
Evaporation is not widely used. It is particularly important for those users who are required to pay for disposal of all wastes, including wash waters. However, the highly concentrated waste may be classified as 'Toxic Waste' by the disposal company (and its licensing authorities) under the local waste regulations. This method should therefore only be used after seeking advice.
There are two types of evaporators available, atmospheric or vacuum.
These consist of an evaporation pot incorporating a heating element and a thermostat. The temperature in the pot is kept below 60°C to avoid unwanted emissions. These evaporators vent the water vapour produced into the atmosphere through an exhaust pipe. This can be fitted with a charcoal scrubber to clean up the exhaust vapour. This type of evaporator is relatively cheap and easy to operate but consideration must be given to the type of exhaust vapours produced, such as ammonia, and the amount of energy needed to evaporate the waste liquids. Use with caution because of the potential exhaust gas hazard.
Vacuum and distillation
These types of evaporator have a vacuum source as well as an evaporation chamber. Some are heated electrically but others use waste heat generated from the cooling coil to save energy. A vacuum source means that evaporation occurs at a lower temperature and reduces the tendency for noxious gases to be produced. The solid waste or liquid slurry end product can be sent away for disposal whilst the pure liquid distillate can often go down the drain or be used to make up new fixer; it should not be used to make up developer or developer replenisher solutions.
The key to minimising the volume of wash water used while maximising print permanence is to use the ILFORD optimum permanence wash sequence, and avoid the use of hardeners.
Paper: conventional washing
Fibre based papers require washing in running water at 18°C to 24°C for 60 minutes (double weight) or 30 minutes (single weight), and washing times should be extended if the water temperature is below this range.
Paper: ILFORD optimum permanence sequence
For double weight MULTIGRADE IV FB, water consumption can be reduced by over 85% by using this sequence, all solutions and the wash water being at 18-24°C:
1.Fixing - ILFORD HYPAM (1+4) without hardener, intermittent agitation: 1 minute
2.First Wash - Good supply of fresh, running water: 5 minutes
3.Rinse – Using WASHAID, intermittent agitation: 10 minutes
4.Final Wash - Good supply of fresh, running water: 5 minutes
Film: conventional washing
When a non-hardening fixer, such as HYPAM, has been used, films require washing in running water for 5-10 minutes at a temperature within 5°C of the processing temperature.
Film: ILFORD optimum permanence sequence
Using this sequence, water consumption can be reduced by over 85%. The recommended development temperature is 20°C, and all other solutions and the wash water should be within 5°C of the developer temperature.
1.Process the film in a spiral tank.
2.Fix using ILFORD HYPAM fixer, without hardener.
3.After fixation, fill the tank with water at the same temperature as the processing solutions, and invert it five times.
4.Drain the water away and refill. Invert the tank ten times.
5.Drain and refill it for the third time and invert the tank twenty times. Drain the water away.
A final rinse in water to which a few drops of ILFORD ILFOTOL wetting agent has been added will aid rapid and uniform drying.
Use of Hardeners
Hardeners should only be used in fixers to prevent mechanical damage and reduce drying times when putting films through processing machines. They are not recommended for black and white paper processes. If hardeners are used, the washing time must be increased considerably to ensure complete washing. Incomplete washing will produce images that will degrade with time.