(a) Use equation 1 of this section to calculate the weighted-average HAP content for all aluminum surface coatings used in the past 12 months.
Where:
HAPSC = weighted-average organic HAP content for all aluminum coating materials, kilograms of organic HAP per liter of coating solids.
m = number of different aluminum primers, top coats, and clear coats used in the past 12 months.
Voli = volume of aluminum primer, top coat, or clear coat i used in the past 12 months, liters.
Di = density of coating i, kilograms per liter.
Wi = mass fraction of organic HAP in coating i, kilograms of organic HAP per kilogram of coating.
p = number of different thinners, activators, and other coating additives used in the past 12 months.
Volk = total volume of thinner, activator, or additive k used in the past 12 months, liters.
Dk = density of thinner, activator, or additive k, kilograms per liter.
Wk = mass fraction of organic HAP in thinner, activator, or additive k, kilograms of organic HAP per kilogram of thinner or activator.
Solidsi = solids content of aluminum primer, top coat, or clear coat i, liter solids per liter of coating.
(b) Compliance is based on a 12-month rolling average. If the weighted-average organic HAP content does not exceed 1.22 kilograms of organic HAP per liter of coating solids, then you are in compliance with the emission limit specified in § 63.5743(a)(2).