Under the Emergency Response Planning Guidelines #2, what is the maximum airborne concentration of chlorine below which nearly all individuals could be exposed for up to 1 hour without experiencing or developing irreversible or other serious health effects that could impair an individual's ability to take protective action?

Under the Emergency Response Planning Guidelines #2, what is the maximum airborne concentration of chlorine below which nearly all individuals could be exposed for up to 1 hour without experiencing or developing irreversible or other serious health effects that could impair an individual's ability to take protective action?

• A. 4 ppm
• B. 5 ppm
• C. 3 ppm
• D. 10 ppm

Answer: (C)

Emergency Response Planning Guidelines use three exposure levels to guide protective actions. The description given matches the level that defines the concentration below which nearly all individuals could be exposed for up to an hour without experiencing irreversible or other serious health effects that would impair their ability to take protective action. For chlorine gas, that ERPG-2 value is three parts per million. The other numbers would correspond to different ERPG levels and do not describe this specific protective-action threshold.

Emergency Response Planning Guidelines use three exposure levels to guide protective actions. The description given matches the level that defines the concentration below which nearly all individuals could be exposed for up to an hour without experiencing irreversible or other serious health effects that would impair their ability to take protective action. For chlorine gas, that ERPG-2 value is three parts per million. The other numbers would correspond to different ERPG levels and do not describe this specific protective-action threshold.