Here is the OSHA interpretation on the subject. While it would be advisable for the containers to be closed as it may discharge a foul smell, OSHA says the following:

The Bloodborne Pathogens standard, 1910.1030(d)(4)(iii)(B)(1), requires regulated waste containers to be ". . . (a) Closable; (b) Constructed to contain all contents and prevent leakage of fluids during handling, storage, transport, or shipping; (c) Labeled or color-coded in accordance with paragraph (g)(1)(i) of this standard; and (d) Closed prior to removal to prevent spillage or protrusion of contents during handling, storage, transport, or shipping." The intent of the term "closable" is to ensure that waste contained within the receptacle is not spilled during the handling and storage of the container. While the container is in use, it is not a requirement that it be closed. However, in between uses and once the container is removed from use (i.e., before transport and during storage), it must be closed.

If the exterior of the container (plastic bag) becomes contaminated, as is possible in a surgical suite, the employer must ensure a secondary containment system is available. This secondary container must also be closable and must prevent spillage during handling and transport [29 CFR 1910.1030(d)(4)(iii)(B)(2)].

Our recommendations, however, is to use a step-on bio hazard container available on sale with us or in the market in each room treatment room. Each of these containers must be lined by a bio hazard bag. At the end of each day, the bio hazard wastes may be emptied into a medical waste box supplied by the medical waste transporter. This bio hazard box maybe kept in a clean and dry storage room, where medical wastes maybe stored before the transporter pick up.