Working level month (WLM) means an exposure to 1 working level for 170 hours (2,000 working hours per year divided by 12 months per year is approximately equal to 170 hours per month).
Level I means a component of the federal PASRR requirement. Level I refers to the identification of individuals who are potential nursing facility admissions who have indicators of mental illness or developmental disabilities (42 CFR 483.128(a)).
Working level (WL) means any combination of short-lived radon daughters in 1 liter of air that will result in the ultimate emission of 1.3E+5 MeV of potential alpha particle energy. The short-lived radon daughters are—for radon-222: polonium-218, lead-214, bismuth-214, and polonium-214; and for radon-220: polonium-216, lead-212, bismuth-212, and polonium-212.
Barrier Level means the Barrier Level as specified in § 1 of the Product and Underlying Data.