General room ventilation does not effectively control personnel exposures to hazardous levels of airborne chemicals. Consequently, laboratory hoods are required to contain chemical vapors and gases at ...

In such cases, the contaminant should be removed at the source, before it has the opportunity to mix with the general room air ... systems for hazardous materials and air contaminants must be ...

(CBS) -- A large hazardous materials response ... The liquid migrated toward the laundry room and eventually spread throughout the ventilation system, police said. As a precaution given that ...