Biosafety and Disposal

Bacterial Culture Guide Biosafety and Disposal

Table of Contents


The need for precautions when experimenting with bacterial cultures depends upon the source and nature of the biological material, the experimental procedure, and the laboratory/containment conditions. Since every situation is different, the risks need to be identified for each individual strain and the appropriate precautions need to be taken before any work begins.

More information on risk assessment and precautions can be found in the Center for Disease Control (CDC) publication Biosafety in Microbiological and Biomedical Laboratories.29 The text of this publication is available in its entirety on the CDC website at

ATCC assigns a biosafety level (BSL) to each bacterial strain for the purposes of packaging for safe shipment. ATCC follows federal biosafety guidelines and takes several factors into consideration when assessing a potential hazard, and in some cases the ATCC assigned biosafety level is more restrictive. Generally, ATCC only ships and stores bacterial strains with a biosafety level assignment of 1, 2, or 3.

Biosafety Level 1

  • Work involving well-characterized bacterial strains not known to consistently cause disease in immunocompetent adult humans. 
  • Work can be conducted on the bench top using aseptic technique, no special containment equipment or facility is required. 

Biosafety Level 2 

  • Work involving bacterial strains that pose a moderate hazard to healthy adult humans. 
  • Work should be conducted in designated biological safety cabinets within laboratories with restricted access. 

Biosafety Level 3 

  1. Work involving indigenous or exotic agents that may cause serious or potentially lethal disease via inhalation. 
  2. Work should be conducted in biological safety cabinets localized inside a specialized BSL-3 containment facility within laboratories with restricted access.

As the recipient of a bacterial strain, take into account not only the nature of the material but also the manipulations employed during its handling when assessing the potential laboratory risk. Keep in mind that there will be situations where the intended use of an agent may require more stringent precautions than associated with the assigned biosafety level.29

Disposal of Infectious Materials

All bacterial cultures, stocks, and potentially infectious materials need to be properly decontaminated prior to disposal. The written method for proper decontamination should be available in the laboratory and BSL facility. Several methods of sterilization include autoclavation, chemical disinfection, incineration, or any other validated decontamination method. More information on the disposal of bacterial cultures can be found in the Center for Disease Control (CDC) publication Biosafety in Microbiological and Biomedical Laboratories.29