Considerations for personal protective equipment when handling cytotoxic drugs

Cytotoxic drugs are widely used in the healthcare industry. However, whilst effective in treating diseases, the toxicity of these drugs can present a significant health risk to the manufacturers, pharmacists, and other healthcare professionals who handle them. Occupational exposure can occur in many ways; staff are at most risk when preparing the cytotoxic drugs. The greatest hazards arise through the formation of dusts (e.g., in the event of defective injection vials containing dry solids), liquids (e.g., on transfer and dispensing of the dissolved substance), aerosol formation (e.g., when dissolving the dry solids), or when containers containing cytostatics are inadvertently dropped. Once exposed, a wide range of potential side effects could occur, including abdominal pain, vomiting, and allergic reactions. To mitigate the risk of exposure, it is vital that companies involved in the manufacturing and handling of cytotoxic drugs ensure that staff are given the highest possible levels of protection.

Cytotoxic drugs are hazardous substances as defined by the Control of Substances Hazardous to Health Regulations 2002 (COSHH) [www.hse.gov.uk/healthservices/safe-use-cytotoxic-drugs.htm]. Under COSHH regulations, employers must assess the risks from handling cytotoxic drugs for employees and take suitable precautions to protect them. This includes carrying out a full risk assessment that will identify any potential hazards, define who may be harmed and how, as well as flag up if existing precautions are adequate or whether more could be done. Risk assessments should continue to be carried out periodically to ensure that the protective measures are still suitable.

Controlling exposure
It is important that all possibilities of removing the hazard altogether are exhausted before considering ways of limiting staff exposure. The following hazard-control hierarchy can be used as a guide to good practice:

Eliminate-remove the risk altogether if possible.

Substitute-find a safer substitute (e.g., a less toxic material or a different working method).

Safeguard-put technical solutions in place that protects the worker (e.g., mechanical ventilation, machinery guards, and remote controls).

Warn and educate-implement worker training and install suitable alarm and warning systems.

It is the responsibility of management to implement safe working methods and to reassess procedures in response to changing conditions such as the emergence of new hazards. However, employees must also be trained and educated to accept responsibility for identifying risk situations and for taking the necessary safety precautions. This includes a responsibility for using the personal protective equipment (PPE) provided in the correct manner and being aware of its use, its limitations, and its correct disposal.

Choosing the optimum PPE
PPE is the final line of defence when it comes to protecting personnel from toxic substances. PPE, whilst primarily intended to prevent the body from coming into contact with hazardous chemicals and dusts, also plays a vital part in protecting the manufacturing process from human contamination, including hair, shedding skin, and clothing fibres. As such, it is a crucial safety measure that cannot be compromised. The following factors should be considered when choosing coveralls and protective garments.

Protection from particle intrusion. Barrier efficiency against migrating particles, such as those from clothing or human skin, is a crucial performance feature when working with cytostatics. When determining the level of protection from particle intrusion, it is important to look at the Type 5 test results. The Type 5 test specifies the minimum requirements for chemical protective clothing resistant to penetration by airborne solid particles. To test particle intrusion, the Type 5 test method uses sodium chloride particles at 0.6 micron sizes suspended in a fine spray in a test chamber. The 9-minute test (3 minutes standing, 3 minutes walking, and 3 minutes squatting) is repeated on 10 suits. To pass the test, eight out of the 10 suits tested must have on average less than 15% inward leakage into the suits. This means that coveralls that have passed the Type 5 test offer a certain level of protection against fine particulates. It is important to choose a coverall that offers the lowest level of inward leakage for the best possible protection when working with cytostatic drugs.

Material. While most coveralls look similar, the material used makes a difference in determining the end protection level. There are three common types of material: microporous film (MPF), spun bond–melt blown–spun bond (SMS) and Tyvek (DuPont), which is a synthetic material made out of flashspun high-density polyethylene fibres. When tested against BS 6909, these materials perform differently. MPF (sometimes known as LMPF) is made using a spunbond polypropylene and a film of polyethylene. Due to the structure of the material, it is not breathable and has a high particle shed count. SMS is a breathable material but has poor liquid repellency. Due to the short fibres in the material, it sheds fibres quickly and is, therefore, unsuitable for cleanroom environments. Tyvek, manufactured only by DuPont, is made up of ultrafine endless high-density polyethylene fibres using specific spinning and bonding technology. Because of the endless fibres, it has a low particle shed count.

Comfort. Whilst protecting both the worker and the process is crucial, a further, important issue is having coveralls that are comfortable. If workers are comfortable, they are more willing to wear the protective garments and protection is, therefore, heightened. The garments should ideally be designed to be durable enough to allow for a range of movement and flexibility, without compromising safety through ripped seams. At the same time, the fabric should offer sufficiently high levels of permeability to both air and water vapour to allow it to “breathe.”

The German Apothekenbetriebsordnung (ApBetrO, regulation on the operation of pharmacies), which has been in force since June 2012, has also set out specific hygiene conditions for working with cytostatics. According to the regulation, protective clothing must also comply with the following requirements:

·        Liquid-tight at arms and front

·        Long sleeves

·        Closed at the front                 

·        Tight seal at cuffs             

·        Low-linting

·        Barrier against pure and dilute cytostatics as well as fine particles

·        Smooth surface (prevents particles from adhering to the surface)

·        Optional: comfortable to wear, antistatic treatment, sterilizable.

Ian Samson, DuPont consultant for the EMEA and Russia regions, www.chemicalprotection.dupont.co.uk.