Prevention Guide - Safe Handling of Hazardous Drugs - Irsst

2. RISKS RELATED TO THE USE OF HAZARDOUS DRUGS
2.3.3 Worker Contamination
The risk for workers depends on the toxicity of the drugs to which they are exposed and their level of exposure to
these drugs. Exposure depends on a number of factors:
‣ the work performed: preparation, administration, cleaning, etc.;
‣ its frequency and duration;
‣ the quantity of hazardous drugs handled;
‣ compliance with good work techniques: proper hoods, wearing of protective equipment, work techniques.
The skin is the known primary exposure route. Contamination of the hands and, less frequently, the forearms and
forehead account for 87% of contaminated body areas (Fransman, 2004).
This exposure often results in whole body contamination, detectable through the presence of drugs in the urine. In
18 studies, 16 detected the presence of drugs in the urine, including 4 where the workers did not handle any drugs.
These cases are thought to represent indirect contamination through contact with contaminated surfaces.
There is no safe exposure standard. In view of the seriousness of the potential effects, prudent practice requires
that the exposure be reduced as much as technically possible. Turci et al. use the acronym ALARA, i.e., “as low
as reasonably achievable” (Turci, 2006).
While an acceptable level has yet to be determined by occupational health and safety organizations, publications
in this regard should be monitored by the scientific community. For example, in its August 15, 2006 update, the
United States Pharmacopoeia mentions a maximum acceptable environmental contamination threshold of 1
ng/cm 2 for cyclophosphamide. This exposure value can be verified in Quebec workplaces using the environmental
monitoring tests developed by the INSPQ at the request of the Working Committee (see Appendix 5). To help the
institutions interpret their results, a summary of the contamination values from 34 studies was published in the
INSPQ toxicology newsletter (Bussières et al., 2006b)
The members of our Committee do not recommend measuring biological contamination levels in workers (other
than for research purposes), as it is currently impossible to interpret the results (see Section 15).
2.3.4 The Importance of Prevention
All of these studies clearly demonstrate the need for the stringent application and intensification of preventive
measures.
The risks for the worker can be substantially reduced if he works in a controlled environment, such as a vertical
laminar flow hood, in a properly ventilated area, using the recommended protective equipment and safe work
techniques.
For example, a recent study performed in Holland reported an 8- to 25-fold reduction in the level of glove
contamination during work in the hood and a 25- to 6000-fold reduction in contamination in the hood from 1993-
1999 to 2005. (Fransman, 2005). This improvement can be attributed to concentrating drug preparation in the
pharmacy, heightened worker awareness and a tightening of the preventive measures.
The same attention must be paid to every step of the medication circuit. The study also reported contamination in
workers providing care to patients who had received antineoplastic drugs. Here, as the risk is not perceived to be
as high, the preventive measures were not always as stringent.
Training also plays an important role in reducing contamination. Favier (2002) demonstrated a 3.2-fold reduction
in the frequency of hand contamination and a 7-fold reduction in the amount of drug found on the hands. Prior to
the training, 100% of gloves and 70% of hands were contaminated, despite the use of standard means of
protection. Following training regarding proper handling procedures, 45% of gloves and 20% of hands were
contaminated.
There are closed-circuit systems for preparation and administration which have proven effective in significantly
reducing the level of contamination in both the workers and the work environment. The PhaSeal ® system has been
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