Biological agents not involved in fire
Knowledge and understanding
|Biological agents not involved in fire||
Understand all associated hazard knowledge
A biological agent is any microorganism, cell culture or human endoparasite, including any that have been genetically modified, that can cause infection, allergy, toxicity or otherwise pose a hazard to human health. Biohazards arise from exposure to a range of pathogenic organisms. Acute or chronic infectious diseases may be caused by bacteria, viruses, protozoa, prions or fungi. The pathogen can enter the body via skin contact, puncture wounds, cuts, inhalation of aerosols or dusts and also by ingestion of contaminated food or drink. These pathogens are found almost everywhere in varying forms; they are a biohazard when the numbers exceed what is regarded as an ‘infective dose’.
Most biological agents arise from single-celled organisms of various types, which are collectively referred to as ‘pathogenic organisms’. These can be grouped into four different classes:
- Bacteria (e.g. Escherichia coli/E. coli, tuberculosis/TB, salmonella, legionella)
- Viruses (e.g. hepatitis B, hepatitis C, HIV)
- Protozoa (e.g. toxoplasmosis, ringworm, malaria)
- Fungi and spores (e.g. aspergillosis).
- Prions: Transmissible spongiform encephalopathies (TSEs) (Creutzfeldt-Jakob disease CJD)
Included within the above list, there is a serious health risk to firefighters from the transmission of infectious diseases through direct or indirect contact with animals (zoonoses) that are alive or dead and with animal waste. Examples of zoonoses are Lyme disease and salmonella. Contact between pregnant firefighters and animals carrying chlamydia abortus toxoplasmosis or listeriosis can also result in miscarriage or damage to the unborn child.
Categorisation of microorganisms
The Advisory Committee on Dangerous Pathogens issue an Approved List of Biological Agents that is updated regularly. It classifies biological agents in four categories. The hazard Group classification is for wild-type or naturally occurring pathogens made under CoSHH whilst the Class indicates that the organism has been genetically modified:
- Hazard group/class 1 – unlikely to cause disease
- Hazard group/class 2 – can cause disease, may be a hazard to employees, is unlikely to spread to the community and there is usually an effective prophylaxis or treatment available; examples include measles and mumps
- Hazard group/class 3 – can cause severe human disease, may be a hazard to employees, may spread to the community but there is usually an effective prophylaxis or treatment available; examples include hepatitis B and tuberculosis
- Hazard group/class 4 – causes severe human disease, is a serious hazard to employees, is likely to spread to the community and there is usually no effective prophylaxis or treatment available; examples include haemorrhagic fevers (Ebola and Lassa)
Additional hazards are associated with facilities that undertake biological agent research and development. Hazards may include:
- High security levels, including electronic locking mechanisms, that prevent unauthorised access
- Premises containing hazard group 3 and 4 agents are required to maintain negative pressure (up to –100Pa) to prevent biological agents being released outside the building
- Uninterruptible power supplies to laboratory equipment and building facilities
- Laboratories may be regularly disinfected; this generally takes the form of gaseous formaldehyde fumigation over a 36-hour period
- Premises may house various types of animals, used for research purposes
- Gases may be present, including nitrogen, hydrogen, helium and oxygen; these may present a cryogenic hazard
- Chemicals may be used, including acids, bases, alcohols, volatile agents and toxic or carcinogenic organic compounds, such as benzene
- Various radiation sources may be used for tracer experiments
- Liquid nitrogen for cryogenic storage
For transport operations biological materials will show the symbol shown below:
Under the classification, labelling and packaging (CLP) regulations (the European Union version of the globally harmonised system (GHS)), biological materials are generally not placed on the market. However, materials that may have an effect on the public carry the following symbol.
This symbol also covers risks such as germ cell mutagenicity, carcinogenicity, reproductive toxicity and specific target organ toxicity.
Using, researching and handling biological agents are strictly regulated activities. Many of the regulations require controls and actions that will assist a fire and rescue service at an incident. Sites must provide a written contingency plan for dealing with laboratory accidents; the plan will provide operational procedures for:
- Biological agent risk assessment
- Managing and decontaminating workplace and personnel
- Emergency medical treatment for exposed and injured persons
- Clinical surveillance and management of exposed persons
The Dangerous Pathogen Regulations 2002 requires a safety officer/adviser be appointed. The duties of the safety officer/adviser will be to assist the employer.
Employers are required to;
- Carry out risk assessments on the work being undertaken
- Notify local authority fire services in advance, as part of the emergency plan, of substances to be handled that may be a hazard to fire officers in the course of their duties
- Have appropriate decontamination procedures in place
- Have arrangements for disposing of infectious waste.
- Provide expert advice where necessary
The Control of Substances Hazardous to Health (COSHH) and the Genetically Modified Organisms Regulations require the Health and Safety Executive (HSE) to be notified of the intention to use, store or transport certain hazard groups. Sites handling HG 3 and 4 organisms must have staff on call in case of an emergency – it will be essential to liaise with them during any incident.