CSLB C-36 Plumbing ContractorSafetyHard
A plumbing apprentice is cleaning up a spill of PVC primer and cement, which are known to contain volatile organic compounds (VOCs). What is the primary method of controlling exposure to these hazardous fumes in a well-ventilated indoor space?
- AOpening windows and doors to increase general ventilation.
- BUsing local exhaust ventilation directly at the source.
- CWearing a half-face respirator with organic vapor cartridges.
- DWearing a surgical mask.
Show answer & explanationAnswer & explanation
Correct answer: B. Using local exhaust ventilation directly at the source.
While general ventilation and respirators are important, the Hierarchy of Controls prioritizes engineering controls. Local exhaust ventilation (LEV) directly captures and removes contaminants at the source, preventing them from spreading into the breathing zone, making it the primary and most effective control for hazardous fumes.
Why the other options are wrong
- A. Opening windows provides general ventilation but is less effective than local exhaust at containing fumes at their source, especially if the space is large or airflow is inconsistent.
- C. A respirator is a personal protective equipment (PPE) control, which is lower on the Hierarchy of Controls than engineering controls like local exhaust ventilation, and should be used in conjunction with or as a backup to engineering controls, not as the primary method if engineering controls are feasible.
- D. A surgical mask offers no protection against chemical vapors or hazardous fumes.
Hazardous Fume Control (Hierarchy)
A systematic approach to minimizing exposure to hazardous fumes, prioritizing elimination, substitution, engineering controls, administrative controls, and finally PPE.
- Engineering controls (LEV) are preferred over PPE.
- Local exhaust captures at the source.
- General ventilation dilutes, but doesn't remove at source.
- Respirators are last line of defense.
Memory trick: Eliminate, Substitute, Engineer, Administer, PPE.