Procedures involving volatile chemicals, and those involving solid or liquid chemicals that may result in the generation of aerosols, must occur in a laboratory hood, glove box, or other suitable containment equipment. Examples of aerosol-producing procedures include: opening of closed vessels; transfer operations; weighing; preparing feed mixtures; and the application, injection or intubation of a chemical into experimental animals. Class II, type B biological safety cabinets are suitable for the conduct of tissue culture and other biological procedures involving highly toxic chemicals, reproductive toxins, and select carcinogens. The Principal Investigator is to obtain guidance from EHS on the selection and use of Class II biological safety cabinets. For more information on biological safety cabinets, refer to Chapter 16: Biological Safety Cabinets. Primary containment equipment used for chemical carcinogens must display a label bearing the legend: CAUTION – HIGHLY TOXIC CHEMICAL (OR SELECT CARCINOGEN), Authorized Personnel Only. The examples below in Figure 7.1Figure 7.2, and Figure 7.3 are available on the EHS Safety Labels webpage for printing.

Figure 7.1
Examples of postings for storage areas or primary containment equipment where highly toxic chemicals or select carcinogens are present.

A clean bench (Chapter 16, Section III) is a laminar flow cabinet that provides a flow of filtered air over the work service and offers product protection, not personnel protection. Do not use highly toxic chemicals or select carcinogens in them. These are posted by the lab or EHS with the information in Figure 7.2.

Figure 7.2
Example posting for clean benches.