The critical process of setting exposure limits

by Hank Rahe

Click here to enlarge image

The pharmaceutical industry deserves a round of applause for its commitment to employee safety practices in handling hazardous drugs. The world's manufacturers have taken the high road in developing occupational exposure limits for new drugs to ensure employee safety.

The pharmaceutical industry has come a long way in providing employee protection, but it must continue to extend its efforts to include the complete delivery chain of pharmacies and caregivers.

The process of establishing exposure limits requires significant resources but, in the end, provides critical engineering controls and a template for employee training.

The process of setting exposure limits requires data from the profile of the drug substance as well as feedback from the information collected in the clinical phase. Key resources are required to understand the information and make judgments regarding the impact the drug will have on individuals who could become exposed in the workplace.

This data is reviewed to deter mine potential out comes of such exposures, considering both the quantity of drug present and the duration of the exposure. Based on the outcome scenarios, determinations are made considering certain factors, including whether or not the exposure can be life threatening, the ability to reverse the effects of exposure and the long-term impact of exposure on future generations.

Based on this information, a safety factor is selected and added to the hard data conclusions reached by analysis of impacts of both research and experienced-based information. The combination of the data plus a safety factor sets the exposure limit, which becomes the protection goal for the engineering controls systems.

Engineering controls and employee training programs are selected based on the exposure limit and must be implemented at every step of the handling process to ensure that employees are protected. Controls are required at any point where the quantity of the drug substance present exceeds the exposure limit and the drug can be manipulated in a manner that could cause it to become airborne or touch the employee's skin.

The probability of the entire quantity of the drug being available for inhalation is slight, and a rule of thumb is the amount present can be up to ten times the exposure limit before controls should be considered.

As the exposure limits of these hazardous drugs become lower, the quantities creating the potential exposure become smaller and areas well beyond the manufacturing area can potentially put other employees at risk. Workers in development areas and analytical laboratories handling gram quantities can no longer assume they are safe because of the “small” amounts of drugs they handle. Exposure points such as the paper used in documentation of manufacturing operations can contain significant quantities of highly potent drugs. The paperwork can travel into a number of operations located far from the manufacturing environment and carry contamination into laboratories and offices.

Proper engineering controls for employee protection must be accompanied by training programs covering safe handling practices. Procedures describing the proper handling in emergency situations, such as spills, must be incorporated in a compressive program for working with hazardous drugs. Hazardous materials teams must have the proper tools in terms of personal protective equipment and training to handle potential spills and other emergencies. Local fire and police emergency response teams need to be informed and trained in proper procedures.

The pharmaceutical industry has come a long way in providing employee protection, but it must continue to extend its efforts to include the complete delivery chain of pharmacies and caregivers.

Hank Rahe is director of technology for Containment Technologies Group and is a member of the CleanRooms Editorial Advisory Board.


Easily post a comment below using your Linkedin, Twitter, Google or Facebook account. Comments won't automatically be posted to your social media accounts unless you select to share.