40 CFR § 63.5749 - How do I calculate the organic HAP content of aluminum wipedown solvents?

---
identifier: "/us/cfr/t40/s63.5749"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "40 CFR § 63.5749 - How do I calculate the organic HAP content of aluminum wipedown solvents?"
title_number: 40
title_name: "Protection of Environment"
section_number: "63.5749"
section_name: "How do I calculate the organic HAP content of aluminum wipedown solvents?"
chapter_name: "ENVIRONMENTAL PROTECTION AGENCY"
subchapter_number: "C"
subchapter_name: "AIR PROGRAMS"
part_number: "63"
part_name: "NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES"
positive_law: false
currency: "2026-03-24"
last_updated: "2026-03-24"
format_version: "1.1.0"
generator: "[email protected]"
authority: "42 U.S.C. 7401"
regulatory_source: "57 FR 61992, Dec. 29, 1992, unless otherwise noted."
cfr_part: "63"
---


# 63.5749 How do I calculate the organic HAP content of aluminum wipedown solvents?

(a) Use equation 1 of this section to calculate the weighted-average organic HAP content of aluminum wipedown solvents used in the past 12 months.

Where:

HAP<sub>WD</sub> = weighted-average organic HAP content of aluminum wipedown solvents, kilograms of HAP per liter of total coating solids from aluminum primers, top coats, and clear coats.

n = number of different wipedown solvents used in the past 12 months.

Vol<sub>j</sub> = volume of aluminum wipedown solvent j used in the past 12 months, liters.

D<sub>j</sub> = density of aluminum wipedown solvent j, kilograms per liter.

W<sub>j</sub> = mass fraction of organic HAP in aluminum wipedown solvent j.

m = number of different aluminum surface coatings (primers, top coats, and clear coats) used in the past 12 months.

Vol<sub>i</sub> = volume of aluminum primer, top coat, or clear coat i used in the past 12 months, liters.

Solids<sub>i</sub> = solids content 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 0.33 kilograms of organic HAP per liter of total coating solids, then you are in compliance with the emission limit specified in § 63.5743(a)(1).