40 CFR § 63.2983
What emission limits must I meet?
June 9, 2020
(a) You must limit the formaldehyde emissions from each drying and curing oven by either:
(1) Limiting emissions of formaldehyde to 0.03 kilograms or less per megagram (0.05 pounds per ton) of fiberglass mat produced; or
(2) Reducing uncontrolled formaldehyde emissions by 96 percent or more.
(b) [Reserved]