Prevention Guide - Safe Handling of Hazardous Drugs - Irsst

15. MEDICAL, BIOLOGICAL AND ENVIRONMENTAL MONITORING
A wide variety of hazardous drugs is handled in every pharmacy department, as well as in the care units
and outpatient clinics. In the medium term, the assessment of worker exposure could be performed by
identifying one or more of the most frequently used drugs and periodically measuring their concentrations
in the blood or urine. Currently, however, there are no reference values in this regard. In addition, the
finding of minute traces (in nanograms or picograms) must be interpreted with a great deal of caution.
In theory, this type of monitoring could probably provide a more accurate picture of actual occupational
exposure than environmental monitoring and confirm the effectiveness of the corrective action being
taken in the workplace. The results would take into account the actual effectiveness of both the protective
measures for each worker and the work techniques. However, a biological monitoring protocol has yet to
be validated and this type of monitoring may present drawbacks for the workers which are not yet welldocumented.
In particular, relatively little is known about the relationship between the level and duration
of worker exposure and the likelihood of developing a health problem (Fransman, 2007). In addition,
often not enough is known regarding how low doses of these drugs are metabolized in the body
(Dranitsaris, 2005). The interpretation of the results in a group of workers may help circumvent the risk
of adverse effects likely to result from analysis of a single individual and would, in all likelihood, be more
reliable. Despite this, we are currently not recommending introducing this type of monitoring and these
tests should only be used in a research setting.
Precautionary reassignment of pregnant or nursing workers
While improving preventive measures reduces exposure, the very importance of these measures and the
necessity for periodic monitoring via environmental measurements and evaluation of work techniques
confirm the existence of risk. Reducing contamination depends on many factors (facilities, the use of
good techniques by the worker and her colleagues, protective equipment, thorough cleaning, etc.) and
failures or disruptions can occur. Pregnant workers are entitled to be assigned to avoid any exposure –
even accidental.
Precautionary reassignment prior to conception
Despite several requests in this regard, the working group is not issuing any formal recommendations in
this guide regarding the reassignment of workers who are planning a pregnancy. In our opinion, such a
measure will become less relevant as exposure control improves.
Exclusion of workers who have been treated for cancer
While it is true that the drugs used to treat a cancer can increase the risk of developing a new cancer, the
level of occupational exposure is so marginal in comparison to the doses used during treatment that we do
not feel it warranted to prohibit these individuals from resuming their work. However, the clinician
should have the final word in this regard.
Environmental monitoring
Environmental monitoring allows the evaluation and measurement of chemical contamination by
hazardous drugs. In view of the seriousness of the potential effects, the Act respecting Occupational
Health and Safety and caution itself suggest reducing exposure as low as reasonably achievable
(ALARA) (Turci, 2006). While an acceptable level has yet to be determined by occupational health and
safety organizations, a scientific review of the publications in this regard should be carried out. For
example, the August 15, 2006 update proposed by the United States Pharmacopoeia discusses a
maximum acceptable threshold for cyclophosphamide of 1 ng/cm 2 (USP, 2006).
A number of organizations recommend keeping a record of environmental measurements. The ASSTSAS
Hazardous Drug Committee supports this recommendation. To this end, the Committee has requested the
help of the INSPQ Toxicology Laboratory in developing a technique for detecting and measuring traces
of antineoplastic agents using samples taken from work surfaces. Tests have been developed to measure
three agents. They are available from the INSPQ and are based on the procedures described in Appendix
5.
15-2 ASSTSAS PREVENTION GUIDE – SAFE HANDLING OF HAZARDOUS DRUGS