Once again, it depends on the agent. All bedding is hazardous to the employee to some extent because the dust in the bedding, if kicked up into the breathing zone, will include particles with very allergenic proteins excreted in rodent urine. These are emptied at an exhausted bedding dump station by trained animal care staff using PPE. The bedding is bagged and disposed of into the regular trash dumpster. The bedding from animals treated with many pharmaceuticals (not toxic/carcinogenic) and other chemicals are handled in the same way. The bedding from animals treated with pathogenic organisms must be handled in a BSC, autoclaved and then discarded into the regular trash. The bedding from animals treated with a toxic/carcinogenic chemical that is largely excreted into bedding or with toxic metabolites that are largely excreted must be handled in a fume hood or exhausted BSC unless the literature indicates that degradation of the compound within the time frame of the experiment and animal cage changeout. These are bagged for for a waste vendor. In some cases, only the lab workers are allowed to change out the animals. Regardless of who is providing animal care support, written protocols must be posted and followed.
In terms of the bedding handling, how do you treat the bedding? As hazardous waste if it is a hazardous chemical? Is only the first cage change after drug administration treated as hazardous? Do the staff ever wear more than nitrile gloves, goggles, lab coats? Do they have to do the bedding change in a fumehood, ducted BSC? What kind of extra protection would be afforded the animal care husbandry staff if deemed necessary (e.g., double gloves, respirators?)
List [mailto:DCHAS-L**At_Symbol_Here**list.uvm.edu] On Behalf Of Dodge, Janice
Sent: Thursday, December 09, 2010 2:26 PM
Subject: Re: [DCHAS-L] Chemical Safety and Lab Animals
Our Biosafety Officer and Lab Safety Officer review all proposed animal use protocols wherein research animals are treated with chemicals or other hazardous agents. We have provided all researchers with a description of “standard precautions” which they may check on their protocol form if they think no extra precautionary measures are needed for the work beyond standard lab and animal care PPE and handling protocols. If they are using agents that require protective methods beyond the standard, they must submit an appendix to the animal care protocol (we’ll help them write this) describing the extra precautions needed, eg. work only in a BSC or fume hood, special PPE, special practices or disposal steps, certain types of posting, extra training or supervision, emergency response procedures.
Often the researchers believe standard precautions are adequate and we do not. Then we ask them to “beef up” their protocols and tell them how and why. They have to do this to get approval of the animal use in their experiments by the IACUC.
These reviews take some time because we have to research the hazards related to the particular agents. We look at degree of toxicity, method of administration, number of doses, amount likely to be excreted in bedding (if known), length of treatment, number of animals, as well as work practices and potential for injury or exposure…in other words we perform a risk assessment.
This program has worked pretty well for us. It’s time consuming, but we have much better protection of our workers, in particular our animal care staff, than we once did. Researchers tend to ignore what happens after they walk away from the rat. If they are asked to think about the ultimate fate of a chemical injected IP or subcutaneously in a rat, they simply say that the doses are small (rats are small, right?) so small amounts of chemicals could not possible effect humans (even though they are used in the experiment to have a biological effect and many rats are injected at once, perhaps for days or weeks).
I hope this helps.
Laboratory Safety Officer
Florida State University
I am trying to get information from peer institutions about how they manage worker safety in regard to exposure to chemicals administered to lab animals. Does anyone have any expertise in this issue?
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