Particle Size Distribution of Serratia marcescens Aerosols Created During Common Laboratory Procedures and Simulated Laboratory Accidents

Abstract

Andersen air samplers were used to determine the particle size distribution of Serratia marcescens aerosols created during several common laboratory procedures and simulated laboratory accidents. Over 1,600 viable particles per cubic foot of air sampled were aerosolized during blending operations. More than 98% of these particles were less than 5 ,u in size. In contrast, 80% of the viable particles aerosolized by handling lyophilized cultures were larger than 5 ,u. Harvesting infected eggs, sonic treatment, centrifugation, mixing cultures, and dropping infectious material produced aerosols composed primarily of particles in the 1.0to 7.5-,u size range. Considerable information has been compiled in recent years concerning the aerosol spread of microorganisms during routine bacteriological and virological procedures. Operations involving withdrawal of material from vaccine bottles (2, 6, 12), inoculation of mice and the inoculation and harvesting of eggs (6, 12), handling of lyophilized cultures (14, 15, 18), pipetting (2, 10, 16), use of the inoculating loop (2, 11), blending (2,

Containment of Polioviruses After Eradication and OPV Cessation: Characterizing Risks to Improve Management

“…Such large‐particle aerosols (along with small‐particle aerosols) are created by release of liquids under pressure (sprays), dropping and breaking containers or spilling contents, force mixing of suspensions with pipettes, harvesting cell cultures, manipulating fluids with needles and syringes, mechanical blending, shaking, pouring, and opening containers. ( 101,161,162,197,203 ) Dropping or spilling clinical samples, infectious cell harvests, or vaccine production concentrates have the greatest potential for exposure as they combine extensive surface contamination with droplet aerosol production. ( 203 ) The high settling velocity and the brief duration of air‐borne infectious droplets (>5 μ) precludes room ventilation from being an effective control measure within laboratory space.…”

Laboratory-associated infections and biosafety

“…Numerous procedures in the laboratory generate aerosols that cause infection when inhaled (Table 5) (19,39,79,133). Depending on their size, droplets will either settle out of the air quickly (Ͼ0.1 mm in diameter) or evaporate in 0.4 s (Ͻ0.05 mm in diameter) (19).…”

Biological safety cabinetry.

“…Only a few individual laboratory-associated infections have been reported, because centrifuge accidents typically result in multiple cases (86,160). Leaking or broken centrifuge tubes release infectious particles (98,176). Enclosing the centrifuge tubes in safety centrifuge cups eliminated aerosols created by broken centrifuge tubes, as the generated aerosols were contained within the safety cups (177).…”

“…Studies focusing on viral (44,172) and fungal (105) hazards, cross-infection experiments (106,109), and simulated accidents in the laboratory (12,98) have been reported in scientific journals. Numerous comprehensive reviews on the hazards in the laboratory have been published in journals (32,175,177,195,216), as chapters in books (3,15,33), as government studies or guidelines (136,156,160), and as entire books dealing solely with laboratory safety (36,61,132,143).…”