Clinical Microbiology Reviews, July 2008, p. 403-425, Vol. 21, No. 3

SUMMARY
INTRODUCTION
DEVELOPMENT OF CONTAINMENT MEASURES: BRIEF HISTORIC OVERVIEW
PRINCIPLES AND METHODS OF BIOSAFETY
BIOSAFETY MEASURES
Risk Assessment
Biological Containment
Viruses.
Bacteria and protozoa.
Physical Containment
Categorization of microorganisms (non-GMOs).
Categorization of GMOs and definition of harmful gene products and microorganisms.
Laboratory design and primary and secondary containment.
Categorization of biosafety containment levels.
APPROACHES FOR BIOSAFETY EVALUATION
Compliance with Procedures and Training
EXPERIMENTAL AND OBSERVATIONAL DATA ON THE EFFECTIVENESS OF CONTAINMENT MEASURES
Do Single Devices and Procedures Function Effectively?
BSCs.
Cell sorters.
Respiratory protection devices.
Does the Laboratory as a Whole Afford Effective Containment?
Are Laboratory Workers and the Environment Protected against Infection?
Reviews.
Surveys.
GMO-associated laboratory accidents.
Accidents with risk category 4 organisms.
DISCUSSION
ACKNOWLEDGMENTS
REFERENCES

We examined the available evidence on the effectiveness of measures aimed at protecting humans and the environment against the risks of working with genetically modified microorganisms (GMOs) and with non-GMO pathogenic microorganisms. A few principles and methods underlie the current biosafety practice: risk assessment, biological containment, concentration and enclosure, exposure minimization, physical containment, and hazard minimization. Many of the current practices are based on experience and expert judgment. The effectiveness of biosafety measures may be evaluated at the level of single containment equipment items and procedures, at the level of the laboratory as a whole, or at the clinical-epidemiological level. Data on the containment effectiveness of equipment and laboratories are scarce and fragmented. Laboratory-acquired infections (LAIs) are therefore important for evaluating the effectiveness of biosafety. For the majority of LAIs there appears to be no direct cause, suggesting that failures of biosafety were not noticed or that containment may have been insufficient. The number of reported laboratory accidents associated with GMOs is substantially lower than that of those associated with non-GMOs. It is unknown to what extent specific measures contribute to the overall level of biosafety. We therefore recommend that the evidence base of biosafety practice be strengthened.

FIG. 1. Context of biosafety measures. Based on a risk assessment, wild-type biological agents and GMOs are assigned to one of four risk categories. Work is subsequently performed under conditions that reflect increasing containment demands, i.e., BSL-1 to -4. Risks are contained by a set of measures employing biological and physical barriers and laboratory practices.