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Guidelines in the Handling of Hazardous Substances

I wrote this article in 2009, as a student, for a rotation project. While it was of course years prior to USP <800>, the information in this article is just as true today as it was then. Because it was written as a student project, the writing style is more academic in nature than I usually write for this website, but I hope you will nonetheless find lots of good information in here you can use in your pharmacy. I made minor edits for clarity and readability.


I decided to post this article because:

1) there are a lot of pharmacies gearing up for USP 800 taking effect, and

2) my article on hazardous drug handling in the community pharmacy has been so popular. This article expands on the information provided in it.


Background


Hazardous drugs pose significant threats to healthcare workers, oftentimes on a daily basis, and substantiate the need for proper education among all involved. Workers may be exposed through transporting, distributing, unpacking, preparing, administering, and disposing of those drugs. Effects on healthcare workers include fetal and reproductive toxicity as well as cancer. Occupational cyclophosphamide exposure, for example, has been estimated to lead to as many as 50 additional cases of cancer each year for every million workers exposed. Moreover, controlled surveys have revealed an increased frequency of complaints of minor ailments, such as chronic coughing, headaches, and dizziness among healthcare workers who handle hazardous drugs at work.

These risks can be reduced by educating workers as well as developing institutional protocols that aim to identify hazardous drugs and limit occupational exposure to them. The aim of this article is to provide an overview of ways in which both the institution as well as the worker can strive to reduce occupational exposure to hazardous drugs. It is important to note that the responsibility lies with both; it is up to the institution to develop sound practices, and it is up to the workers to read and follow carefully the practices set forth by the institution.


Educational Resources


The American Society of Health­-Systems Pharmacists (ASHP) publishes and updates guidelines on handling hazardous drugs that are based on the primary literature as well as government reports. This is a great place to begin to gather general information, get a good overview of hazardous drugs in the workplace, and obtain many references. The guidelines are updated occasionally, with the newest guidelines being current to 2004.

[PC]: USP <800> can be downloaded for free here and is currently probably the best place to start, though both the ASHP and NIOSH guides (described below) are excellent as well.


The Material Safety Data Sheet (MSDS) is another great resource specific to a particular drug. It helps the institution assess the level of risk of exposure to the drug in question and gives resources on potential routes of exposure, the acute and chronic health effects due to exposure, proper first aid measures, fire and explosion data, appropriate personal protective equipment (PPE) and handling procedures, and proper spill procedures. The MSDS may be obtained from the manufacturer or distributor of the chemical.


[PC}: The MSDS has been slightly reformatted since I originally wrote this article and is now termed a Safety Data Sheet (SDS). Because of when this article was written, MSDS is used throughout.


The National Institute for Occupational Safety and Health (NIOSH), a division of the Centers for Disease Control, also publishes guidelines on preventing occupational exposure to hazardous drugs in the healthcare setting. These guidelines, including a printable .pdf, are available for free download online. In it, they describe the potential for exposure including routes of exposure, evidence that workers get exposed, and recommendations on everything from handling and packaging to proper selection of ventilation cabinets.


Other publications by NIOSH include guidelines on PPE in the workplace, medical surveillance for healthcare workers exposed to hazardous drugs, and specific guidelines regarding the handling of Micotil 300, an antibiotic used in veterinary medicine with health risks to humans.

The Occupational Safety and Health Administration (OSHA) publishes a technical manual, a hazard communication standard, and an occupational exposure to hazardous chemicals in laboratories standard. Guidelines are also published by the Oncology Nursing Society.


What is a Hazardous Drug?

NIOSH classifies hazardous drugs on several criteria:


  • Carcinogenecity

  • Teratogenecity or developmental toxicity

  • Reproductive toxicity

  • Organ toxicity at low doses

  • Genotoxicity

  • Structure and toxicity profiles of new drugs that mimic existing drugs determined hazardous by the above criteria

ASHP’s classifications parallels those of NIOSH. It is up to the individual institution to develop their specific list of hazardous drugs, taking into account the above factors.

The World Health Organization’s International Agency for Research on Cancer (IARC) also provides a complete list of agents they have reviewed for carcinogenicity.


Their classification is based on the following system:

  • Class 1 (carcinogenic to humans),

  • Class 2A (probably carcinogenic to humans)

  • Class 2B (possibly carcinogenic to humans)

  • Class 3 (unclassifiable as to its carcinogenicity to humans)

  • Class 4 (probably not carcinogenic to humans).

It is not exclusive to therapeutic agents, but is nonetheless a great resource to use when assessing carcinogenicity.

The National Toxicology Program, part of the Department of Health and Human Services, publishes the Report on Carcinogenicity (RoC), currently in its 14t​h​ edition. The website is a bit more difficult to navigate than the IARC, but would be useful to certain institutions.


Exposure Routes


Drugs may enter the body through inhalation, ingestion, contaminated food products, hand­-to­mouth, or dermal contact. The route of exposure that is most important is dependent on the drug. For example, a report published in 1992 found no significant dermal absorption of doxorubicin, vincristine, or vinblastine, implying a different route of exposure for those drugs. Because the primary route is different for every drug and oftentimes is unknown, it is prudent to protect workers against all possible routes of exposure.

The most important routes of exposure in the workplace (the way in which most drugs are absorbed) are believed to be inhalation and dermal absorption. Standard sampling methods have generally detected either none or very low levels of drugs in the aerosol and gaseous phase in the pharmacy and clinic environment; however, there is some concern that many of the hazardous drugs are volatile and thus wouldn’t be captured on a standard sampling filter. Thus the idea of inhalational exposure is a topic of current debate and limited evidence.

As far as dermal absorption, numerous studies have confirmed the presence of hazardous drugs on the surface of biological safety cabinets, tables, and counter tops. The ability for contamination to spread to many surfaces in the work area further emphasizes the need for proper institutional standards and training for employees.


Assessing the Workplace and Developing a Comprehensive Safety Plan


Before hazardous drugs are ordered the workplace needs to be assessed to determine if it can properly handle their presence. Employees need to be trained, and policies need to be in place with the proper committees responsible for updating those policies. The culmination of this results in the comprehensive safety plan for the hospital.

The safety plan must be developed with input from all involved, including those involved in transport, preparation, administration, and disposal. The departments involved might include pharmacy, medical staff, nursing, housekeeping, transportation, maintenance, safety, a