CfA Safety: Respiratory Protection

The primary method for the protection of laboratory personnel from hazardous airborne contaminants should be to minimize the amount of such materials entering the laboratory air. When effective engineering controls (such as fume hoods and local exhausts) are not possible, suitable respiratory protection must be provided.

In the absence of a fume hood or other adequate engineering controls, masks and monitoring are required; there is a definite sequence that must (by law) be followed:

  • Persons who will be in contact with the chemical(s) must be identified.
  • Monitoring must be done to determine if exposure to the chemical(s) exceeds 50% of the Threshold Limit Value (TLV) or the Permissible exposure Limit (PEL), whichever value is more stringent.
  • If monitoring indicates exposure above allowed levels, persons identified above must be sent for medical evaluations to be sure that they do not have a physical condition that would be aggravated by the use of a mask (medical screening).
  • Such persons must then be provided with masks specifically designed to protect against the chemical(s) in question.
  • Each person for whom a mask has been ordered must be fitted and trained in its use.
  • (Please note that the "surgeon's masks" available from hardware stores and various Harvard stockrooms are not made to protect the user and are not sufficient to protect against hazardous chemicals.)

Call the Safety Office (5-7478) for help in obtaining monitoring, medical evaluation, fitting, and training.


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