Controlling Risks of Work with Biological Agents and Hazards
You need to describe the control measures which will be used to protect people, animals, plants and other aspects of the environment from exposure to biological agents and hazards in the work. COSHH requires that the risks of exposure to biological agents and hazards is prevented or where this is not reasonably practicable then adequately controlled to reduce the risk of exposure to an acceptable level. SAPO and other environmental laws require similar specific control measures for biological hazards. The purpose of the biological COSHH risk assessment process is to enable you to select the most suitable controls or combination of controls that are proportionate to the risks. Control measures are systems and actions used to reduce the risks of exposure to biological agents and hazards. These include engineering controls such as containment laboratories and microbiological safety cabinets, management controls such as safe operating procedures, training, supervision, and personal protective equipment like lab coats, gloves and spectacles.
Containment Levels
Specific control measures and containment levels are required for activities with biological agents and hazards under COSHH, SAPO and other relevant laws and these are described in the HSE, Scottish Government and DEFRA guidance. You must select the appropriate containment level for your work which is derived from the hazard group classification of the biological agent or what is suspected about the possible presence of a biological agent in the hazard. COSHH specifies minimum containment levels required for the following types of work.
- Containment level 1 (CL 1) for work with a hazard group 1 (HG 1) biological agent.
- Containment level 2 (CL 2) for work with a hazard group 2 (HG 2) biological agent.
- Containment level 3 (CL 3) for work with a hazard group 3 (HG 3) biological agent.
- Containment level 4 (CL 4) for work with a hazard group 4 (HG 4) biological agent.
- Containment level 2 (CL 2) for laboratories which do not intentionally propagate, concentrate or otherwise increase the risk of exposure to a biological agent but work with materials in respect of which it is unlikely that a hazard group 3 (HG 3) or hazard group 4 (HG 4) biological agent is present.
- Containment level 3 (CL 3) or 4 (CL 4), where appropriate, for laboratories which do not intentionally propagate, concentrate or otherwise increase the risk of exposure to a hazard group 3 (HG 3) or hazard group 4 (HG 4) biological agent but where the employer knows, or it is likely, that such a containment level is necessary.
- Containment level 3 (CL 3) for activities where it has not been possible to carry out a conclusive assessment but where there is concern that the activity might involve a serious health risk for employees.
There are minimum and recommended control measures which are required for work at each containment level and these are specified in the relevant HSE, Scottish Government and DEFRA guidance. Biological containment laboratories, animal facilities and plant facilities must therefore be classified into one of the three containment levels (CL 1 - 3). Basically, containment level 1 is for low risk work, containment level 2 is for medium risk work, and containment level 3 is for high risk work. The containment level and all the necessary controls required for the activity must be specified in detail in the biological COSHH risk assessment and implemented. In some cases depending on the nature of the biological agents or hazards or the activity it may be necessary to use additional control measures. In some other cases there are provisions to obtain permission for derogation from HSE to apply less than the minimum containment and control measures normally required for the containment level. Requests for derogations must be made to the HSE and must be fully justified on the basis of risk assessment and may only be applied on receipt of written agreement from the HSE. However there is permission for general derogations for certain types of work which are detailed in the relevant HSE guidance and subject to the risk assessment do not require specific request to HSE.
Control Measures
Control measures will predominantly reflect the risks, activity and potential routes of exposure of people, animals or plants or release to the environment. Control measures must be selected on the basis of the specific requirements of the legislation which are detailed in relevant HSE, Scottish Government and DEFRA guidance. Broadly, the control of risks involves a systematic approach which requires the application of the most effective control measures which are reasonably practicable and the selection of risks control measures should be done using a hierarchical approach. The most effective control measures must be used in preference to the least effective ones starting with elimination, followed by substitution, engineering controls, administrative controls and lastly personal protective equipment. Once you have decided that you cannot eliminate hazardous activities or substitute less hazardous activities, you should implement control measures that prevent or minimise exposure to risk. The control measures must be selected in this order of priority. Control measures must be selected in this order of priority according to the level of risk identified in the biological COSHH risk assessment to ensure that they are effective. When deciding on the sort of control measures that you intend to use the most important requirement is that control of exposure should be achieved by the most effective means and this must not be only by the use of personal protective equipment where more effective measures can be used. In practice a combination of control measures are generally used to reduce the risks of exposure to the biological agents and hazards. In some cases depending on the activity additional control measures may also be necessary or in other cases less stringent control measures may be applied. Once you have decided on the appropriate controls then they must be implemented and used. The controls must be used to reduce the level of exposure to the lowest level that is reasonably practicable and at least to a level which is adequate to protect human health, animals, plants and other aspects of the environment.
You should provide details of where the work will be done and how the biological agents and hazards will be properly contained. Consider if the work will be done in a containment laboratory, animal facility, plant facility or will specialised facilities be required. General control measures should include systems and procedures for safe use, handling, storage and transport of biological agents and hazards, sharps, maintenance of equipment, reducing numbers of exposed persons, duration of exposure and quantities to the minimum, controlling the working environment, appropriate disinfection and decontamination, safe collection, storage and disposal of contaminated waste, displaying hazard warning signs and using appropriate hygiene measures. Consider if the work will require total enclosure (eg glove box, anaerobic cabinets, flexible film isolators or class 3 safety cabinets), partial enclosure (eg class 1 or 2 safety cabinets or cage cleaning cabinets), local exhaust ventilation (eg exhaust ducting for laboratory equipment) or general ventilation (eg containment laboratories, animal or plant facilities). You should also consider whether you will need to control access to the area where the work will be done by limiting it to authorised persons only. Where an effective vaccine is available the workers may need to be offered immunisations to individuals who may be exposed to biological agents at work.
Control measures which are used to prevent or control exposure to biological agents and hazards are properly maintained, examined and tested to ensure that they are working efficiently. The control measures subject to detailed examination and testing include engineering controls, local exhaust ventilation (LEV), which includes microbiological safety cabinets and extract ventilation for equipment, and respiratory protective equipment (RPE). The precise nature of the maintenance, examination and test and degree of competence of the tester will vary depending on the nature of the equipment. Controls must be visually inspected periodically and maintained according to the manufacturer’s instructions. LEV must be regularly maintained and thoroughly examined and tested at least once annually. Respiratory protective equipment must be thoroughly examined and tested at suitable intervals. People and contractors carrying out examinations and tests must be competent. Where equipment is simple and its operation easily checked a local examination might be sufficient. However, where more complex systems are in use an examination by an external specialist contractor is likely to be required. This is generally undertaken by the institution where such systems form an integral part of a buildings fabric such as the air handling systems in containment laboratories and microbiological safety cabinets which are externally ducted to the roof of a building. Personal protective equipment (PPE) used to protect workers should be stored, checked and cleaned in such ways as to prevent the equipment being a contaminated by biological agents and hazards. There must be an effective fault reporting system established. The requirement to inspect and test extends to administrative controls where it may be work practices that ensure adequate control and in these circumstances such systems should be subject to regular monitoring and inspection. Suitable records of any testing and examination of controls must be kept.
Local Exhaust Ventilation and Microbiological Safety Cabinets
Local exhaust ventilation (LEV) is equipment used to control airborne contaminants by containing and capturing hazardous solids, liquids or gases. There are many types of LEV such as fume cupboards (FC) and microbiological safety cabinets (MSC). You should provide details of the LEV which will be required to control aerosols of biological agents or hazards. There are three basic types of MSC which offer different types of protection to the operator, work and environment.
- Class 1 (Operator and environment protection).
- Class 2 (Operator, work and environment protection).
- Class 3 (Operator, work and environment protection).
- Class 1/3 hybrid (Operator and environment protection only, or operator, work and environment protection).
Microbiological safety cabinets function by using airflows to capture hazardous aerosols generated by work, transferring microorganisms away from the operator before trapping them in a high efficiency particulate air (HEPA) filter. Selection requires an assessment of the work and operator protection requirements but also the proposed location as draughts or physical obstacles may compromise cabinet performance. MSC must be tested after installation to ensure they provide operator and environment protection. Commissioning tests need to be repeated whenever an MSC is moved or there is a major change to the local environment. LEV and MSC must be selected, installed and maintained according to the relevant British Standards. Note that fume cupboards and clean cabinets have different functions from MSC and must not be used instead of MSC for work with biological hazards. Clean cabinets are not LEV or safety cabinets but are designed solely to provide a clean working area so they do not protect people or the environment and must not be used for work with biological hazards.
Special Controls
You should provide details of any special control measures that you intend to use for your work. Foe example work with toxic or carcinogenic hazards requires a high level of control. When selecting the appropriate measures for controlling the risks of carcinogens or toxins, the potential for long term and possibly fatal effects must be taken into account. Priority should be given to the elimination or substitution of the carcinogenic biological agents or hazards in question with a non-carcinogen. If alternatives are not reasonably practicable then this must be stated with explicit reasons in the risk assessment. If no suitable alternative to the carcinogen is available, exposure to the carcinogenic biological agents or hazards must be prevented by the best practicable means and following the hierarchy of control measures. Because of the nature of the risks posed by carcinogens, it is particularly important to select the most effective measures possible. Strict control measures should be adopted including for example, totally enclosed process and handling, extensive cleaning and disinfection procedures, safe storage and disposal and prohibition of eating and drinking. The storage, use and disposal of carcinogenic substances require careful control. Carcinogenic substances used in the workplace should be kept to the minimum needed for the process. Clearly identify the areas in which exposure to carcinogens may occur and take measures to prevent the spread of contamination within and beyond these areas. The number of people likely to be exposed to carcinogenic agents and the duration of their exposure must be kept to the minimum necessary for the work. Non essential personnel must be excluded. Where appropriate, store and transport them on site in closed containers, clearly labelled and with clearly visible warning and hazard signs. Clearly label and securely store carcinogenic waste products until they are removed according to the proper procedures for removal of hazardous waste.
Personal Protective Equipment
You should provide details of the personal protective equipment (PPE) which will be required to protect the body, hands, eyes, face etc such as laboratory coats, gowns, gloves or spectacles, goggles and face shields. The risk assessment may specify that PPE is required to control exposure to a biological agent or hazard when it is not possible to achieve adequate control over exposure by any other means and then it should be used only in addition to other appropriate controls. The PPE must be suitable to adequately protect against specific biological agents or hazards. You should consider the potential routes of exposure to the biological agents and hazards when deciding on appropriate PPE. All PPE must be carefully selected and properly maintained, serviced and cleaned. Workers should be fully trained in its use and limitations.
Respiratory Protective Equipment
You should provide details of the respiratory protective equipment (RPE) which will be required to protect the respiration such as disposable masks, respirators or breathing apparatus. RPE should only be used where other more effective control measures cannot be used and generally only as an only additional control. The RPE must be suitable to adequately protect against the specific biological agents and hazards. Simple disposable dust masks do not provide protection against biological agents and hazards and should not be used. You need to consider the potential routes of exposure to the hazardous substances when deciding on appropriate RPE. Disposable respirators or filtering face piece (FFP) masks are available in three classes P1, P2 and P3 providing differing protection factors. For protection against biological agents and hazards reusable half or full face respirators must be fitted with filters suitable to protect against the particular hazard present in the work. Detailed advice on this should be sought from the respirator manufacturer. All RPE must be carefully selected to be appropriate, properly maintained, serviced and cleaned. Workers should be fully trained in its use and limitations. RPE must be thoroughly examined and tested at suitable intervals. RPE which relies on a tight-fit to the face for protection such as disposable filtering dust mask, reusable half face and full face masks, and breathing apparatus must be face-fit tested for each individual wearer. Testing must be carried out by trained competent persons. Once face fit tested to a specific type of RPE then a certificate of test must be obtained and recorded. The worker must only wear the type of RPE on which they were tested and they may need to be retested where required. Face fitting RPE does not work equally well for all individuals or situations and an alternative option is a powered respirator hood which supplies filtered air at positive pressure to the breathing zone of the wearer by a soft or hard top hood that encompasses the head.
Storage and Transport of Biological Agents and Hazards
You should consider at this stage the quantity you need and the facilities required to store the biological agents and hazards. Special conditions may also be required such as ventilation and security. You should provide details of how you will safely transport the biological agents and hazards. For example what special packaging and multiple containment will be required for internal and external transport of the biological agents and hazards. Special controls may also be required such as, hazard signage, carrying spillage kits and PPE.
Destruction or Inactivation of Biological Agents and Hazards
You should provide details of how you will destroy the biological agents and hazards used in the work. The proper inactivation and disposal of waste is very important part of work. There are chemical and physical methods of inactivating biological agents and hazards. Validation and monitoring of effectiveness is required to prove that inactivation method works. All biological agents must be inactivated by a validated means and this needs to be explicit by using effective procedures for both validation and monitoring and keeping adequate records of these for inspection on request by the HSE. The effort involved in effective validation and monitoring depends on the risks and inactivation method used. Records must be kept.
Disinfection
Disinfectants must be appropriate for the relevant biological agents or hazards, animals or plants used in the work. The effectiveness of many disinfectants can vary considerable depending on the biological agent, concentration, exposure time, pH and presence of organic matter, liquids or solids. Disinfectants may be used for inactivating biological agents and hazards in solid and liquid materials and also on contaminated surfaces and equipment. The effectiveness of some disinfectants rapidly diminishes after dilution to working concentrations. Validation procedures are generally more difficult to achieve for disinfectants than for autoclaving. Information on the efficacy of a disinfectant can be obtained from the manufacturer’s instructions, published data or in house testing. In many cases disinfectants are used just as an additional control measure rather than the sole means of inactivating biological agents such as where disinfectants are used prior to autoclaving. Inactivation is defined as achieving a sufficient % kill commensurate with the risks although 100% kill is normally required. The % kill to be achieved must be defined and appropriate methods of validation and monitoring that demonstrate this is achieved need to be specified and employed.
Autoclaving
Autoclaving is the most effective inactivation method and by far the easiest and least time consuming to both validate and monitor. For these reasons it is strongly recommended that all biological agent or hazard contaminated waste including all liquid waste and waste destined for incineration be autoclaved unless there is a very good reason to use another method. It is generally accepted that any biological agent, except TSE which are a special case, will be inactivated by autoclaving under conditions that maintain 121ºC for at least 15 min with full steam penetration. Note, the minimum 15 min excludes the time required to reach 121ºC, and the above conditions must be maintained even in the most inaccessible positions of the load. TSE will be inactivated by autoclaving at 134ºC. Inactivation is defined as achieving a sufficient % kill commensurate with the risks although 100% kill is normally required. The % kill to be achieved must be defined and appropriate methods of validation and monitoring that demonstrate this is achieved need to be specified and employed. Records must be kept.
Validation of autoclaving should be carried out using thermocouple mapping. This involves placing multiple independent thermocouples at various sites, including the most inaccessible, within a typical load and recording output during a standard run to determine if all sites maintain the required temperature for the required time. This is usually done by a maintenance engineer as part of the annual maintenance contract and the printout recording the output from each thermocouple will be provided and should be kept as a record. Because steam penetration varies it is important that validation be conducted using a load that represents the most difficult encountered in normal use.
Monitoring of autoclaving should be carried out on each run to confirm that both the correct temperature and time has been employed. This is very easy if your autoclave includes a built in thermocouple linked to a chart or digital recorder which monitors each run and provides a printout or you can download the information electronically that can be kept as a record. If your autoclave lacks this then you have two options. Install a suitable digital recorder linked to a thermocouple that can be fitted to many but not all older or small autoclaves but make sure you choose one that provides a continuous printout, recording the temperature throughout the run. Alternatively you could place a suitable commercially available autoclave indicator in each load and keep a log book that records the results of each run. Most commercially available indicators including standard autoclave tapes are not adequate for monitoring inactivation of waste, because they change colour either at temperatures considerably lower than 121ºC, or within minutes of reaching 121ºC, or in the absence of steam penetration, and therefore do not confirm that the appropriate conditions have been maintained for a sufficient time. A suitable indicator is Browne TST (Time, Steam, and Temperature) test strips. Note that there are several versions of these and you need to ensure you are using the appropriate strips for the temperature and time (eg 121ºC for 20 min or 134ºC for 5 min). These indicators can be obtained from commercial laboratory suppliers.
You should provide a brief statement in this section about the disinfection or autoclaving methods including and validation and monitoring which will be used in your work. For autoclaving you should use one or both of these standard statements provided below which you should not modify.
‘All contaminated materials, including waste destined for incineration will be inactivated by autoclaving (100% kill) prior to disposal of waste or cleaning and recycling of reusable laboratory equipment. Autoclaves will be validated by annual thermocouple mapping and each run will be monitored by continuous chart or digital recording of the temperature/time profile.’
or
‘All contaminated materials including waste destined for incineration will be inactivated by autoclaving (100% kill) prior to disposal of waste or cleaning and recycling of reusable laboratory equipment. Autoclaves will be validated by annual thermocouple mapping and each run will be monitored using Browne TST (Time, Steam, and Temperature) test strips (TST indicator 121ºC for 20 min or 134ºC for 5 min).’
Waste Management and Disposal
All aspects of waste management need to be safely carried out including labelling, safe handling, storage, transport and disposal. Waste containing biological agents and hazards should be properly inactivated using a validated means before disposal. You should describe what waste containers will be used such as waste bags, bins or sharps bins. You should also briefly describe how your waste will be disposed such as whether it will be hazardous or non-hazardous waste, biological, chemical or radioactive waste. Please see the SEPS waste website for further details about waste management and disposal.
Health Surveillance, Monitoring Exposure and Immunisation
Health surveillance may be required for certain occupational diseases or adverse health effects such as infection, cancer and hypersensitivity, to check that people exposed to biological agents and hazards are not harmed during their work. This is usually where there is an identifiable disease or adverse health condition related to work, valid techniques are available for detecting indications of the disease or condition, there is a reasonable likelihood that the disease or condition will occur under the particular work, and where surveillance is likely to further the protection of health of workers. Health surveillance may involve preliminary and ongoing surveillance, questionnaires, interviews, examination, tests, monitoring and referrals. Health surveillance may be required for workers exposed to hazardous biological agents or certain animals and animal allergens. Monitoring exposure may be required for certain activities such as work involving laboratory animal alergens (LAA).
Immunisation may be useful as a control measure to protect people against infection by certain biological agents. For example, hepatitis B vaccine can offer valuable protection against infection for those people who work with human blood and tetanus vaccine is important for protecting against the risks of tetanus in the environment. Vaccines must not be considered as a primary defence against infection but only as an additional control measures. Please see the Occupational Health Service website and contacts for information and advice on health surveillance and immunisation.
Emergency Procedures
You need to describe the control measures and emergency procedures which will be used to protect people and the environment from exposure to the biological agents and hazards in the work in an emergency. You should provide details of the control measures that will be required to deal with accidents and emergencies that could cause people or the environment to be exposed to biological agents or hazards or an accidental release of biological agents or hazards. The manager, principal investigator and workers are responsible for ensuring that incidents and emergencies are properly dealt with since these are the experts in the biological agents and hazards and the work. You need to assess the potential for accidental exposure and implementing emergency procedures for your work. Emergency plans and procedures must be prepared in advance.
The primary objective of the emergency procedures is the containment of the biological agents and hazards and the minimisation of risks to people and the environment. You should consider all of the relevant factors which may include assessing situations, instructions, informing others of accidents, isolation of area, evacuation, seeking assistance, PPE, RPE, preventing spread of contamination or spills, decontamination of work area or laboratory, safe waste disposal, first aid treatment and medical treatment if required. Anyone not concerned with the emergency action should be excluded from the area. Only people essential for dealing with the emergency of carrying out repairs and other essential work may be permitted in the affected area. They must be provided with appropriate personal protective equipment and any necessary equipment. Emergency and spillage procedures should be specified in standard operating procedures and spillage kits will be required. It is necessary to provide important emergency procedures as clear written instructions on display. For example a spillage procedure can be provided on a laminated instruction sheet which can be placed where the hazardous work is done on the wall above a bench or on a piece of equipment. Appropriate training must be provided in all accident and emergency procedures. All workers must understand and be able to implement the emergency procedures. If an emergency occurs, procedures must be put into effect as soon as possible to minimise harm and return the situation back to normal as quickly as possible. Accidents and emergencies must be reported immediately or as soon as practicable to supervisors, safety coordinators and managers and using the accident reporting form on the Safety and Environmental Protection Service (SEPS) website.
You should provide details of the first aid procedures which would be needed to deal with the specific biological agents and hazards in this work in case of an accident or emergency. Training must be provided in all the relevant emergency first aid procedures. You should consider all of the relevant factors to establish effective emergency first aid procedures. This may include removing contaminated clothing as quickly as possible, removing contamination from skin, eyes and mouth by thorough washing with water, dealing with minor cuts and small puncture wounds, washing wounds with soap and water and dressing wounds. Use PPE if required when helping injured persons. Seek help promptly where required from first aiders, GP or hospital. Emergencies should be referred to hospital and call ambulance if necessary. Explain the incident and biological agents or hazards to the medical staff and if possible give them with a copy of the Biological COSHH risk assessment.
Emergency Contacts
You should provide the names and contact details of people to contact in case of an accident or emergency. This must include the name of the principal investigator or manager who is in charge of and understands the work together with details of other relevant persons including the workers doing the work and colleagues involved in the work. Your emergency contacts should not normally include the names of safety advisers or coordinators since they are not responsible for the work or for implementing your emergency procedures and are unlikely to know about the specific work or biological agents and hazards involved. The information and contact details of managers, safety advisers and coordinators, security, and emergency services etc are provided separately for example in emergency arrangements posters and websites.
Information, Instruction, Training and Supervision
You should provide details of the information, instruction, training, and supervision required for the work. All workers and visitors must be provided with adequate information, instructions, training and supervision to enable them to carry out their work safely. This should include local rules, safe working practices and standard operating procedures on the hazards, risks and effective application of control measures and emergency procedures. Standard operating procedures are required for every aspect of the work relating to high containment laboratories. It is important that information, instructions and training is appropriate to the level of risk and in a form which will be understood by those involved in the work. Information should be kept up to date taking into account any significant changes in the work. The control measures will not be effective if those involved in the work do not know their purpose, how to use them properly or the importance of reporting faults. Records of information, instruction and training should be kept. All workers and visitors must be adequately supervised. The principal investigator or manager must decide on the level of supervision required to do the work and this should be proportionate to the risks of the work, the containment level and competence of workers. Some work may not be carried out without direct personal supervision or not be started without the advice and approval of supervisor, while other work can be carried out without direct supervision. Some work may require more than one person to carry it out safely.