According to the CDC Biosafety in Microbiological and Biomedical Laboratory (BMBL, 5th ed.), although risk of laboratory infection from working with cell cultures in general is low, risk increases when working with human and other primate cells, and primary cells from other mammalian species.[1] The BMBL cites reports of infection of laboratory workers handling primary rhesus monkey kidney cells, and the bloodborne pathogen risks from working with primary human cells, tissues and body fluids are widely recognized. As these materials are commonly used in biomedical research, the appropriate biosafety requirements for handling these materials are often subject to debate within the scientific community. In order to clarify the University’s position on these matters, the Institutional Biosafety Committee (IBC) has created the following guidance.

Background / Regulations

In 1991, the Occupational Safety and Health Administration (OSHA) issued the Bloodborne Pathogens (BBP) Standard to protect employees who have occupational exposure to human blood or other potentially infectious materials. While human blood, most body fluids, unfixed human tissues and organs were clearly included within the scope and application of the standard, the inclusion of human cell lines was ambiguous.

In 1994, OSHA issued an interpretation of the applicability of the BBP Standard towards human cell lines. According to the interpretation, human cell lines are considered to be potentially infectious and within the scope of the BBP Standard unless the specific cell line has been characterized to be free of hepatitis viruses, HIV, Epstein-Barr virus, papilloma viruses and other recognized bloodborne pathogens.[2] In addition, the BMBL recommends that human and other primate cells should be handled using Biosafety Level 2 (BSL2) containment and practices.[1]


In consideration of the aforementioned regulatory interpretation, consensus guidelines and other factors, the UCLA IBC has adopted the following policy:

Human and nonhuman primate cells and tissue cultures must be handled in accordance with the OSHA BBP Standard and under BSL2 containment and practices for cell culture experiments and ABSL2 containment and practices when these materials are used in animal experiments. These experiments require IBC approval prior to initiation of work.

Certain well-established human cell lines may be eligible for an exemption from this policy and therefore may be downgraded to BSL1 containment and practices for cell culture experiments and ABSL1 containment and practices when used in animals if the following criteria are met:

  • ATCC or similar vendor has designated the cell line as BSL1.
  • The cells have been tested and deemed free of hepatitis viruses, HIV, Epstein-Barr virus, papovaviruses, and herpesviruses. The results to these tests must be provided to the IBC and testing must be performed every three years (coinciding with the 3-year IBC review).
  • There is an extremely low possibility of the cells being exposed to other pathogens/biological materials that could result in contamination of the cell line (i.e., there may not be any other BSL2 or higher materials or cells handled in the facility).

All requests for an exemption to this policy must be reviewed and approved by the IBC prior to downgrading the cells to BSL1.


  1. Biosafety in Microbiological and Biomedical Laboratories, 5th Edition
  2. OSHA Letter of Interpretation

Approved 6/6/08; Revised 10/15/15