The control of substances hazardous to health
The Control of Substances Hazardous to Health Regulations (COSHH) is a key health and safety law introduced in the 1990s to protect employees from exposure to a range of hazardous substances. A hazardous substance is one that has the potential to cause harm and can be a solid, liquid, gas, fume, vapour, dust or micro-organism and can endanger health by being absorbed or injected through the skin or mucous membranes, inhaled or ingested (Figure 7.1)
In addition to frequent exposures to biological agents through blood and body fluid, there are a number of other hazardous substances that healthcare workers may be exposed to, including cleaning agents, anaesthetic gases, cytotoxic agents, natural rubber latex proteins, diathermy/surgical smoke fumes and formaldehyde.
Under the COSHH regulations, employers have a duty to reduce the risk of ill health from exposure to hazardous substances at work and follow a hierarchy of controls (Figure 7.2). Employees have a duty to follow safe working practices and should report any concerns relating to exposure to hazardous substances to their manager and/or their union safety representative.
Furthermore, certain hazardous substances can be harmful to new or expectant mothers and child through exposures in utero or through breast feeding.
Proteins found in natural rubber latex (NRL) can cause serious allergies, whether through direct contact with the skin or through inhalation of powders in the gloves. Type I or immediate hypersensitivity reactions to NRL can lead to anaphylaxis.
Other materials in latex and non-latex gloves known as accelerators can also cause skin irritation and type IV allergic reactions, a less severe and more localised skin reaction. This can lead to the skin condition, dermatitis.
For these reasons, it is important that glove selection is subject to a thorough risk assessment. Important issues to consider include the suitability of the glove (does it protect against exposures); the fit and comfort (does it allow dexterity); and whether there are any individuals, including service users, with existing latex allergy who may be exposed. Where staff are allergic to latex, suitable alternative gloves must be provided.
While the use of latex gloves hasn’t been banned by the regulator, the Health and Safety Executive (HSE) recommend that if latex gloves are selected they must be powder free and low protein. A number of NHS organisations have gone ‘latex free’ to protect both the public and staff who may have an existing latex allergy.
Overuse of examination gloves in healthcare settings has also been observed and this can lead to additional problems such as breakdown of the skin’s natural barrier. Deciding whether gloves are required for the task alongside appropriate selection is key.
As frequent hand washing and glove use are known to increase the risk of irritant contact dermatitis, employers should carry out regular skin surveillance on the hands of healthcare workers. Midwives should also regularly check their hands and report signs of dermatitis to their employer.
Often referred to as ‘gas and air’, nitrous oxide has the potential to be harmful to the health of midwives, especially through frequent and prolonged exposures in poorly ventilated environments. The HSE has set a daily exposure limit for nitrous oxide and employers need to monitor staff exposures to ensure that limits are not exceeded and ventilation and scavenger systems are effective. Cylinders to be used in home or other less controlled environments may also be fitted with portable scavenger units. Where cylinders are transported in vehicles, midwifery staff must be trained in the safe transport of medical gasses.
Disinfecting agents, such as hypochlorite solutions, used to clean equipment such as birthing pools, surfaces and spillages of blood and body fluids, can cause respiratory, skin and eye irritation.
Incidents can occur when different cleaning agents are mixed, resulting in toxic fumes, or tablet-based hypochlorite agents are mixed with hot rather than cold water.
It is important that all staff are trained in safe use and that solutions are prepared and used as per manufacturer’s instructions. While being mindful of infection control needs, employers also need to take steps to reduce exposures following the hierarchy of controls. For example, by using a disinfecting wipe to reduce the risk of splashes.
The most common type of exposure to biological agents in healthcare is through potentially infected blood and body fluids. HIV and hepatitis B and C are examples of biological agents that can be transmitted to healthcare workers from sharps or needle-stick injuries and splashes to the mucous membranes or non-intact skin. Standard precautions, including the use of personal protective equipment (PPE) such as gloves, aprons, googles and visors, can reduce the risk of exposures. The type of PPE used will depend on an assessment of the risks presented by the procedure. Immunisation against hepatitis B should be offered to all workers at risk of exposure to blood and body fluids.
New regulations to protect midwives and other healthcare workers from the risk of needle-stick injuries were recently introduced in the UK and are covered in more detail in Chapter 9.