risk assessments for hazardous chemicals as required under the

Guidance Note 052 RISK ASSESSMENTS FOR HAZARDOUS CHEMICALS as required under the CONTROL OF SUBSTANCES HAZARDOUS TO HEALTH REGULATIONS (COSHH) and the DANGEROUS SUBSTANCES AND EXPLOSIVE ATMOSPHERES REGULATIONS (DSEAR) June 2006 (Updated January 2008)

This Guidance Note does not cover work with biological agents or radioactive substances – this information can be found elsewhere on the Safety Department website.

This Guidance Note assists with the completion of the Risk Assessment Form for an Activity Involving the Use of Hazardous Chemicals. COSHH requires health risks to be assessed and controlled with regard to all aspects of handling hazardous substances including receipt, storage, use, transport and disposal. Likewise, DSEAR requires assessment and control of fire and explosion risks presented by dangerous substances. The sections below correspond approximately to the sections in the form. The major source of information for completing a COSHH / DSEAR assessment is the Material Safety Data Sheet (MSDS) for the substance(s) in question. Therefore, as an aid to interpretation, an image of each part of a sample MSDS is displayed in the relevant section of the guidance along with some instruction on how to extract the information that it contains. The particular example chosen for this Guidance Note is the Sigma Aldrich Ltd. MSDS for chloroform, but all MSDSs follow a similar structure. It is the responsibility of the person directing the research i.e. the Principal Investigator to ensure that suitable and sufficient COSHH / DSEAR assessments are carried out, remain valid and that the control measures identified are applied. Those carrying out the assessment must be competent to identify hazards and risks and to select appropriate control measures.

1.0 HAZARDS AND RISKS Risk Phrases Each of the substances to be used in the activity should be listed and their Risk Phrases entered in the second column of the table. Risk Phrases are derived from the Chemicals (Hazard Information and Packaging for Supply) Regulations and represent a numbered code describing the types of risk presented by the substance e.g. R38 – Irritating to skin. A complete list of Risk Phrases can be found in the HSE publication EH40 Workplace exposure limits – this document is updated annually. A full list is published in Appendix 1 of this Guidance Note. Risk Phrases for individual substances, together with a description of the hazards, can also be found under the Regulatory Information section on the MSDS for the substance: Note: old chemicals that have been present in the laboratory for a long time may not have satisfactory hazard warning labels and the MSDS may have long disappeared (if it ever existed). If it is difficult to obtain relevant

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safety data or the condition of the substance is in doubt due to its age, it should be disposed and fresh material purchased. Workplace Exposure Limits (WELs) WELs are occupational exposure limits set under COSHH in order to protect the health of workers. WELs are concentrations of hazardous substances in the air averaged over a specified time period (8 hour – long term; 15 minute short term). Again, a complete list of WELs may be found in EH40. If a substance has been assigned a WEL, it will usually be found under the Exposure Controls / Personal Protection section of the MSDS:

WELs were introduced in 2005 to replace the previous old standards – OESs and MELs. The example above refers to OEL (Occupational Exposure Limit) rather than WEL. The MSDS often lists the limits in force in many different countries – the UK limits are obviously the relevant ones. Health Hazard Group The Risk Phrases are divided between low, medium and high in accordance with the severity of the hazards they represent. Broadly speaking, they are divided as follows:

Low health hazard: substances designated as irritant (those that affect the skin and sometimes the eyes).

Medium health hazard: substances designated as corrosive, irritant (particularly by the inhalation route) or harmful (particularly by the inhalation route).

High health hazard: substances designated as toxic, very toxic, carcinogenic, mutagenic and those that may impair fertility or harm the unborn child.

Dustiness / Volatility This information will normally be found under the Physical and Chemical Properties section of the MSDS. In the case of solids, there will often be a subjective description e.g. white crystalline solid and in the case of liquids, the boiling point will be recorded: If the operating temperature of the activity (or part of the activity) is above the nominal 20oC room temperature, then an adjustment will need to be made using the graph in Appendix 2 to determine whether the volatility falls within the low, medium or high range. The matrix on of the risk assessment form is used to determine the overall risk level. Those substances presenting the highest risk will need to receive the greatest attention with regard to control measures. Process factors influencing the risk of exposure At this stage, the boxes should be ticked and any factors identified that are not included in the list should be entered under ‘other’.


Identification of those at risk of exposure Use of any substances presenting a special risk to the pregnant woman or the unborn child needs to be notified to Occupational Health so that it can be verified that all feasible precautions are in place to limit exposure to below the effect threshold. If this cannot be achieved, then any staff in this situation must be informed of the risks and their right to be re-deployed to other work during their risk period. Use of other high risk substances such as carcinogens and sensitisers should also be notified, but only if the risk level is determined to be high by using the matrix in Section 1.1 of the risk assessment form. It may be the case that health surveillance is required under certain circumstances. Other personnel in the workplace such as cleaners, contractors or engineers may be at risk of exposure through a spillage or release (e.g. formaldehyde fumigation in the case of maintenance workers) so need to be considered. Substances presenting fire and explosion risks Substances that are hazardous to safety are subject to DSEAR. These will include substances with the following properties:

• Explosive • Oxidising • Flammable (flash point below 550C). • Highly flammable (flash point below 210C). • Extremely flammable (flash point below 00C and boiling point equal to or less than 350C).

However, many substances that are hazardous to safety are also hazardous to health and the DSEAR principles of control largely mirror those of COSHH with regard to laboratory scale operations, so it is appropriate to consider them together. DSEAR requires employers to:

• Determine what dangerous substances exist in the workplace and what the fire and explosion risks are • Develop control measures to eliminate or control risks and to mitigate effects of any incident • Develop emergency procedures • Provide information, instruction and training • Where appropriate, classify work areas where explosive atmospheres may occur and avoidance of ignition

sources in those areas Hazardous area classification is likely to be applicable to some areas of work within the College i.e. in relation to flammables stores or experimental rigs involving large-scale operations, but is not normally applicable to laboratory scale operations. Classification is not used as a basis for safety in the latter, since it is difficult to completely eliminate ignition sources (though every effort should be made) and ignition protected equipment may not be obtainable. Therefore, the familiar controls should be applied:

• Limit quantities of flammables – 50 litres in each workroom is a benchmark that has existed for many years. • Good handling techniques to minimise spills. Liquid retaining methods - sills, drip trays, bunds etc. • Good general ventilation and LEV – fume cupboards properly used and maintained. Not used as permanent

storage facilities • Adequate supervision of any continuous processes e.g. distillations • Consider and avoid sources of ignition:

• naked flames – use indirect heating methods but beware of electrical ignition risks. Use ignition-protected equipment if available.

• static electricity • hot surfaces • direct / focussed sunlight • other high energy light sources • friction sparks • microwave energy • exothermic reactions • spontaneous combustion

• Segregation of incompatible substances. Further information and guidance on DSEAR may be found in the HSE information sheet: ATEX and DSEAR: Hazardous area classification and Laboratory operations.


Substances subject to other legislation Though not strictly a health issue, it is worth recording whether any of the substances in use are subject to other legislation such as the Chemical Weapons Act or Home Office legislation concerning drug precursors, since this may impact upon licensing, security and ordering procedures for chemicals. 2.0 CONTROL MEASURES There are several ways by which hazardous substances can enter the body: Inhalation This is usually the most serious route of exposure since the lungs are a vulnerable part of the body that readily absorb gases, vapours and soluble dusts which can then be absorbed into the bloodstream and transported to other parts of the body. Skin contact The skin is the next most vulnerable area. Breaks in the surface such as cuts, grazes and certain skin conditions increase the risk. Activities involving ‘sharps’ also present the risk of direct injection. Ingestion This is the least likely route of exposure and the possibility of solid or liquid substances being ingested is very limited. The most likely scenario is hand to mouth contamination. This is unlikely to result in anything beyond local contact i.e. the lips and mouth area and can be controlled by wearing appropriate PPE and good occupational hygiene. Mouth pipetting was outlawed long ago and is not permitted under any circumstances. Elimination, substitution and procedural change Prevention of exposure is the first priority under COSHH. Different approaches can be taken:

Example of using a safer chemical

Ethidium bromide versus SYBR SafeTM

Ethidium Bromide has been commonly used for staining DNA in agarose and acrylamide gels for many years and its toxic and mutagenic properties have been the subject of much discussion. Various safer alternative products have been developed as a potential replacement. A number of College departments have now experimented with Invitrogen’s SYBR SafeTM and have reported equivalent or better results than that achieved with ethidium bromide…..with none of the handling or disposal issues as SYBR SafeTM is non-toxic.

Examples of using a safer form of the same chemical

• Pellets, tablets or flakes in preference to respirable powders. • Purchase of ready-made solutions in preference to weighing and dissolving powders.

Examples of excluding non-essential personnel

Hazard zoning Ensure that the area is well laid out with the most hazardous activities carried out in dedicated parts of the laboratory. These would typically be in the farther reaches of laboratory, segregated from areas where less hazardous activities are carried out and well away from traffic routes / escape routes and doorways. Ensure that fume cupboards are installed in accordance with BS 7258. Exclusion of tasks that can be performed elsewhere Write-up areas should not be located within laboratories – provision of such facilities should be outside the laboratory area so that ‘office’ based tasks can be carried out without the risk of exposure to laboratory hazards. Recording of experimental results at the bench is unavoidable and accepted as being necessary. Maintenance and the Permit-to-Work system Laboratories should be designed in such a way as to minimise the need for non-laboratory staff to enter in the first place e.g. service points located outside the hazardous area. Where entry is necessary, this must be adequately controlled e.g. via the Permit-to-Work process.


Examples of changing the procedure

• Eliminate the need for sharps or substitute blunt needles for sharp needles. • Temperature reduction (to reduce the generation of airborne vapour). • Prevention of surface evaporation by covering.

• Avoidance of the generation of fine dust. Minimising quantities There should be adequate stock control to ensure that only the minimum quantities of hazardous substances to satisfy requirements are held on the premises. Inventories of chemicals assist in preventing re-ordering when the substances required may already exist in the laboratory. Likewise, the quantities of hazardous substances used in individual experiments should be minimised wherever possible. Old chemicals with no hazard labelling )or out of date labelling) should be disposed via the established special waste route. Containment and ventilation Consideration will need to be given as to which activities are of sufficiently low risk to be carried out on the open bench. Those substances that are not harmful via the inhalation route or are used in small quantities or are non-volatile and non-dusty are likely to fall into this category. Simple additional containment measures such as work trays can limit spillages and drips from pipetting. Those parts of the activity that require the use of a fume cupboard or other form of local exhaust ventilation (LEV) need to be identified. These will typically be activities involving larger quantities of volatile or flammable liquids and those involving substances which are harmful via the inhalation route. The MSDS may state ‘only use in a chemical fume hood’ under the Exposure Controls / Personal Protection section: There may be similar statements which indicate the need to use LEV such as ‘do not breathe vapour’, ‘avoid inhalation’ or ‘do not breathe dust’. Note: there is often a reference to ‘safety shower’ and ‘eye bath’ in this section. This sort of provision should be subject to risk assessment. Though safety showers do exist within the College, they present a number of problems and are sometimes in excess of what is needed – they should only be considered where there is a significant risk of large body area contamination. Hand held mains water eye-wash attachments are easier to use and maintain and can be used to flush contaminants from other parts of the body as well as the eyes. If LEV is employed it needs to be appropriate to the task and where relevant, located and installed in accordance with British / European Standards. Re-circulating microbiological safety cabinets should not be used with significant quantities of volatile chemicals since the vapours will simple be re-circulated back into the laboratory. An LEV selection flowchart can be found on the Safety Department website. LEV must be subject to a suitable maintenance regime and should be tested at least every 14 months. This is usually carried out by an external contractor and is often co-ordinated by Estates where fixed items of plant such as fume cupboards are concerned. Performance test results should be affixed to the item of equipment. Emergency procedures should consider the action to be taken in the event of LEV breaking down or being turned off accidentally. Some common activities give rise to specific risks:

Weighing: risk of missing the receptacle and contaminating the balance and immediate area. Weighing of the more hazardous substances can be carried out in a fume cupboard or other partial enclosure such as a ventilated benchtop weighing station. If the air movements cause problems with balance readings, other techniques can be employed e.g.

1. Pre-weigh the receptacle.


2. Using the fume cupboard for protection, place an unweighed quantity of the substance into the tube (approximately equivalent to the amount required). Seal the receptacle.

3. Re-weigh the receptacle plus contents and deduct the weight of the receptacle to ascertain the weight of the substance.

4. Return to the fume cupboard and add the required quantity of water or other solvent to give the final desired concentration.

It must be remembered that facemasks protect only the user and not any other personnel nearby, therefore the above must take precedence. Pipetting: can generate aerosols or result in the dripping of contents. There is potential for contamination of automatic pipettes with the substances in use if they are unwittingly drawn into the body of the pipette. Consider LEV or drip trays, disposal of pipettes / tips, good pipetting techniques and maintenance / cleaning of automatic pipettes. Shaking / Mixing: risk of losing containment if substance spills, leaks or stopper comes loose or if item such as a separating funnel is dropped. Consider using fume cupboard in conjunction with PPE. Centrifugation: risk of tube breakage, leakage, generation of aerosols etc. Ensure that tubes are compatible with both the instrument and the substances with which they will come into contact with. Ensure tubes are correctly balanced. Consider equipment selection, location, PPE, clean-up procedures and training. Filtering: syringe filters present particular risks – see further guidance on Safety Dept website. Use of sharps: obvious risk of skin penetration and direct injection of hazardous substance. Eliminate the need for sharps wherever possible, select the right ‘tool’ for the job, wear appropriate PPE and ensure safe disposal. Elevated Temperature: will increase the rate at which volatile substances form vapours. Lower temperature if possible or if not use LEV, cover or partially cover process, reduce surface area of liquid etc. High Pressure: risk of hazardous substances being ejected and aerosolised. Consider location of equipment and suitable PPE.

The highest degree of protection is afforded by totally enclosed systems such as glove boxes. However, these can be very expensive and cumbersome to use – they are likely to be chosen for only the most hazardous of substances. Storage and transportation Storage issues are addressed in the Handling and Storage section of the MSDS: In this case, the instruction to ‘keep tightly closed’ may seem obvious and of limited use. There may be additional information such as ‘keep away from heat or flame’ in the case of flammables or ‘store in a cool, dry place’. The decision needs to be made on what can be stored on open shelves in the laboratory, what needs to be stored in flammables cabinets, what needs to be contained to prevent drips and leaks, what needs to be held under lock and key etc. Generally:

• Stock quantities of flammables should be held in fire-rated metal cabinets. Those situated beneath fume cupboards that have forced extraction are the best option.

• Acids, alkalis and non-flammable organic liquids should be adequately segregated from each other in suitably resistant cabinets equipped with drip trays. Another good method of minimising the risk of leakage is to leave the primary glass container inside the secondary screw-capped transport container.

• All cabinets should bear suitable signage.


• Bulk solvents should be stored in dedicated storage areas preferably outside the building. • Toxics, carcinogenics, controlled drugs etc. should be stored in lockable ‘poisons’ cabinets.

• Solids presenting lesser hazards may be stored on open shelving (within easy reach). Substances that react violently when mixed should be segregated (information can be found under the Stability and Reactivity section of the MSDS):

Transportation details can be found in the Transport information section of the MSDS: This is of most use to the supplier and will not concern College staff unless there is an intention to transport any chemicals off site in quantities which bring the operation within the scope of the various transport regulations. For information:

RID / ADR – these are the regulations for rail and road transport respectively. IMDG – these are the regulations for transport by sea. IATA – these are the regulations for transport by air. UN1888 – this is the unique number which identifies the substance in question (in this case, chloroform) Class 6.1 - this is the hazard classification for transportation purposes (in this case ‘toxic’) PG: III – this is the Packing Group that the substance falls within – another measure of the hazard level (PGI = high, PGII = medium, PGIII low). Proper Shipping Name – this is the description of the substance for inclusion on packaging and documentation.

If the intention is to transport chemicals off site, the Safety Department should be consulted if there is any doubt as to whether the substances and quantities fall within the scope of the transport regulations. For transportation within a site, the transport regulations do not apply – but COSHH does. Simple practical precautions must be taken:


• Use sealed secondary containment – do not carry primary containers by hand through ‘public’ areas.

• Do not wear disposable gloves in ‘public’ areas where there is a risk of contaminating door handles, lift buttons etc. with hazardous substances. Remove gloves once samples have been placed in secondary containment and put on a new pair when the destination is reached.

Personal protective equipment (PPE) PPE will normally be necessary where adequate control of exposure cannot be achieved by good practice and application of engineering controls such as LEV. It may also be required in temporary situations such as dealing with spillages. It is important to remember that PPE only protects the user and does not afford protection to anyone else in the vicinity – this is one of the reasons that it is some way down the list in the hierarchy of control measures and is often used in conjunction with additional control measures. PPE should be suitable to afford protection against the specific substances that are being used. Gloves Guidance on the selection and use of gloves can be found on the Occupational Health website: http://www.imperial.ac.uk/occhealth/guidanceandadvice/gloveinformationandguidance. Respiratory protection Disposable face masks (known as filtering facepiece or FFP) are probably the most commonly used form of respiratory protection used in the College to protect against particulate material. Guidance on fitting filtering facepiece masks can be found on the Occupational health website: http://www.imperial.ac.uk/occhealth/guidanceandadvice/facemask. Half-masks can also be used for protection against particulate material and organic or acid vapours. It is important to select the correct type of mask and the manufacturers instruction should be consulted. Guidance on fitting and maintaining half masks can be found on the Occupational Health website: http://www.imperial.ac.uk/occhealth/guidanceandadvice/facemask/halfmask Full face masks are sometimes employed in circumstances where the substances being handled affect the eyes as well as the respiratory system e.g. formaldehyde fumigations. Eye / face protection Will usually mean safety spectacles, goggles or full-face visors. Selection should be proportionate to the risk. Consideration will need to be given to staff who wear prescription spectacles. Contact lens wearers should be aware of the need to remove them in the event of eye contamination. PPE requirements are usually found under the Exposure Controls / Personal Protection section of the MSDS: Where selection of respiratory protective equipment is concerned, the relevant standards are the EN (European Union) ones (e.g. EN149 standard for filtering facepieces) rather than the NIOSH (US) standards. It should be noted that when respiratory protection is advised in this section, it does not mean that this is a pre-requisite. The quantity of substance and characteristics of the operation need to be taken into account and other forms of exposure control such as LEV used in preference. Waste disposal Waste disposal may be found under the Disposal Considerations section of the MSDS:


http://www.imperial.ac.uk/occhealth/guidanceandadvice/gloveinformationandguidance

http://www.imperial.ac.uk/occhealth/guidanceandadvice/facemask

http://www.imperial.ac.uk/occhealth/guidanceandadvice/facemask/halfmask

This section needs interpretation as it often contains unhelpful statements such as ‘observe all federal, state and local environmental regulations’ or ‘burn in a chemical incinerator equipped with an afterburner and scrubber’. Beware that the language may be skewed towards the requirements of other countries if the MSDS has not been generated in the UK. In reality, there are only two main options available in the College – discharge to drain or collect for disposal via a specialist waste contractor. Discharges to drain – Further guidance will appear on the Safety Dept website. Specialist waste contractor – disposal can be arranged centrally via Estates (see Guidance Note 037: Chemical Waste Disposal). It is feasible that other small quantities of chemical material could be disposed via the clinical waste route under certain circumstances e.g. polyacrylamide gels, sharps and other disposables contaminated with trace amounts of chemical. Waste chemicals should not be allowed to accumulate on the bench or in a fume cupboard. They should be labelled appropriately and stored in a labelled solvent cabinet or transferred to a chemical waste store if one is available to the department. Hygiene measures This is fairly self explanatory and serves as a check on the physical environment where the work will be carried out and also on general management systems in operation e.g.

• Provision of hygiene facilities

• Specific cleaning requirements for equipment involved in the activity. • Adequate facilities for segregation of personal clothing and PPE and laundering arrangements for PPE where

required. • Rules and signage prohibiting eating, drinking etc.

Monitoring Monitoring takes two forms:

• Air sampling (either in the person’s breathing zone or in the general workplace)

• Biological (analysis of breath, urine, blood samples etc. for the presence of hazardous substances or their metabolites)

Monitoring is a requisite for some substances used in commercial processes (COSHH Schedule 5) but is not necessary if adequate systems are in place to control exposure. It is unlikely that monitoring would be a routine requirement for most College activities. The most likely use of monitoring is to periodically confirm the efficacy of control measures such as LEV. Information, instruction, training and supervision Workers must be provided with sufficient information, instruction and training to carry out the activity safely. Risk assessments and / or standard operating procedures must be provided. On the-job training in the techniques involved in the activity and any relevant local rules should also be provided. Supervision may be required. The level of training and supervision should be commensurate with an individual’s experience. Training records should be maintained locally within the department. Supervisors are expected to monitor whether controls are in place and operating correctly and that adequate training has been carried out on their behalf. Lone working A decision will need to be made as to whether lone working is permitted for the activity in question. Further guidance on lone working can be found on the Safety Department website: https://www.imperial.ac.uk/spectrum/safety/internal/services/guidance/lone_working_gn_sep03.doc Spillage Information on how to deal with spillages may be found under Accidental Release Measures on the MSDS:


https://www.imperial.ac.uk/spectrum/safety/internal/services/guidance/lone_working_gn_sep03.doc

This section requires interpreting with caution. The advice to ‘evacuate the area’ is generally sound. A decision must be made as to the extent of the area to be evacuated. For the kind of scenarios were are likely to envisage within the College, this will often be the immediate area i.e. the laboratory where the event has occurred, though each incident would need to be judged according to circumstance. A spillage within a fume cupboard is obviously far easier to deal with than a spillage on the laboratory floor. Using safebreak bottles (plastic coated to contain contents and broken glass in the event of a drop) reduces the likelihood of a spillage in the first place. Be cautious of the advice to ‘wear self-contained breathing apparatus’. Though there still are breathing apparatus provided in parts of the College, they are few and far between and the general drift has been towards alerting the emergency services to deal with any spillage on a scale that demands the use of such equipment. The reason for this decision is that provision of breathing apparatus presents a number of difficulties:

• It is costly and requires maintaining.

• Users need to be trained and periodically re-trained. • Users need to be medically fit.

Suitable respirators can be used for short periods while a spillage is dealt with, otherwise the area should be vacated until the liquid has evaporated and dispersed to the point where it is safe to re-enter. Clean-up methods may advise ‘absorb on sand or vermiculite’ – it is more satisfactory to have and use dedicated chemical spillage absorption kits that are widely available from commercial suppliers. These contain PPE, absorption / containment materials, scoops and bags for disposal via the hazardous waste route. First aid This is obviously found under the First Aid Measures section and is largely self explanatory:


Be aware of the first aid arrangements for your department and the support arrangements for your campus: http://www.imperial.ac.uk/occhealth/guidanceandadvice/firstaidinformation. Fire fighting There is usually a section on fire fighting measures in the MSDS:

However, there is no specific section in the COSHH form to record fire fighting measures since College staff are not considered to be fire fighters. Though fire extinguishers are provided throughout the College (most commonly water and CO2 types) and basic training is provided by the College Fire Service, ‘first aid’ fire fighting is the most that could be expected. In the event of a serious chemical fire and any doubt over whether it could be tackled or whether the right extinguishers were available, the alarm should be raised and the area evacuated. The fire should then be dealt with by the emergency services. Reviewing the assessment All risk assessments should be periodically reviewed, particularly in the event of significant changes to the activity or in the event of an accident or dangerous occurrence. The latter may either involve an incident in your own laboratory or an incident elsewhere in the College which has been brought to your attention and is relevant to your own activity.


http://www.imperial.ac.uk/occhealth/guidanceandadvice/firstaidinformation

APPENDIX 1


APPENDIX 1 (Cont..)


APPENDIX 2

Source: HSE COSHH Essentials


risk assessments for hazardous chemicals as required under the

Documents