Prevention Guide - Safe Handling of Hazardous Drugs - Irsst

2. RISKS RELATED TO THE USE OF HAZARDOUS DRUGS
2.2.2 Hazardous Drug Entry Routes into the Body
Hazardous drugs may enter the body through skin absorption, ingestion, accidental injection (e.g. needlesticks) or
inhalation.
Skin absorption is the main known penetration route and occurs through direct contact with contaminated
surfaces or objects. For example, contact with the contaminated exteriors of drug vial is one source of
contamination. Contaminated work surfaces, the excreta and bedding of patients treated with antineoplastic drugs,
drug leaks, etc. are other sources of exposure. Most often, the contamination is spread by the hands; this is why
the wearing of gloves and handwashing are such important preventive measures.
Ingestion can occur through eating contaminated food or by putting contaminated fingers or objects (in particular,
pencils) in the mouth.
The significance of inhalation as an exposure route has not been clearly established. A number of studies report
low levels of dust or particles in the air. However, these studies do not usually check for the presence of vapours,
despite the fact that it has recently been determined that some drugs are volatile (Turci, 2003, Kiffmeyer, 2002,
Opiolka, 2000, Connor, 2000). Contamination can occur through the inhalation of drug vapours.
In view of the fact that some hazardous drugs are capable of generating vapours, appropriate preventive measures
must be taken (for example, a biological safety cabinet which does not recirculate the air in the room). The drug
particles can turn into vapour in a few seconds or minutes, depending on the product. A study by Kiffmeyer
(2002) demonstrated that the six drugs studied (carmustine, cisplatin, cyclophosphamide, etoposide, fluorouracil,
fosfomycin) are capable of evaporating. Measurements of cyclophosphamide in gaseous form revealed the
presence of the drug in 7 out of 20 samples.
However, as the drug monographs do not generally include data regarding the volatility of hazardous drugs, it is
not possible to compile a list of these.
2.2.3 Potential Sources of Exposure
Exposure can occur at any step in the medication circuit, i.e., creation of aerosols during the preparation or
administration of hazardous drugs, leaks or spills during transport or handling, contact with contaminated surfaces
or objects, contact with wastes or excreta; etc.
Table 1 summarizes the target workers and primary potential sources of contamination at each step of the circuit.
In addition to those individuals involved in the main steps of the medication circuit, we should not forget the
biomedical engineering workers, who may have to become involved to maintain or repair the pumps and
equipment used to administer the drugs. In view of the local variability of practices and potential sources of
exposure, it is difficult to establish a single risk hierarchy based on potential sources of exposure.
While the majority of hazardous drugs are stored, prepared and administered in a limited number of locations (i.e.,
oncology pharmacy, care units, outpatient clinics, etc.), they can also be administered elsewhere in the institution
(e.g. operating rooms). The guide does not suggest recommendations according to location type. It is up to the
Occupational Health and Safety Program Manager to apply the general recommendations to specific situations
(e.g. using an appropriate transport container between the pharmacy and the operating room, as well as making
appropriate operating room waste receptacles available in the rooms where hazardous drugs are administered,
etc.).
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