Dilution ventilation cannot be used for high-toxicity contaminants.

Dilution ventilation cannot be used for high-toxicity contaminants.

• A. True
• B. False
• C. Not Specified
• D. It Depends

Answer: (A)

Dilution ventilation works by mixing outside air with the room air to lower the concentration of contaminants. It’s most effective when the contaminant isn’t extremely toxic or when emissions are modest, allowing the room air to dilute exposures to acceptable levels. For high-toxicity contaminants, the permissible exposure limits are very low. Relying on dilution alone would require very large amounts of fresh air and still often can’t bring concentrations down quickly enough to protect workers. The contaminant can accumulate near the source and expose people before dilution has a chance to dilute it, making the approach unsafe as the sole control. Because of this, dilution ventilation is not appropriate as the sole method for high-toxicity contaminants; you typically need capture at the source through local exhaust ventilation, containment or enclosure, process changes, or substitution, with dilution and PPE used only as supporting measures if needed.

Dilution ventilation works by mixing outside air with the room air to lower the concentration of contaminants. It’s most effective when the contaminant isn’t extremely toxic or when emissions are modest, allowing the room air to dilute exposures to acceptable levels.

For high-toxicity contaminants, the permissible exposure limits are very low. Relying on dilution alone would require very large amounts of fresh air and still often can’t bring concentrations down quickly enough to protect workers. The contaminant can accumulate near the source and expose people before dilution has a chance to dilute it, making the approach unsafe as the sole control.

Because of this, dilution ventilation is not appropriate as the sole method for high-toxicity contaminants; you typically need capture at the source through local exhaust ventilation, containment or enclosure, process changes, or substitution, with dilution and PPE used only as supporting measures if needed.