Code of Federal Regulations Title 40. Protection of Environment 40 CFR Pt. 63, Subpt. FFFF, Tbl. 4 Table 4 to Subpart FFFF of Part 63—Emission Limits for Storage Tanks

1. Group 1 storage tank

a. The maximum true vapor pressure of total HAP at the storage temperature is ≥76.6 kilopascals

i. Reduce total HAP emissions by ≥95 percent by weight or to ≤20 ppmv of TOC or organic HAP and ≤20 ppmv of hydrogen halide and halogen HAP by venting emissions through a closed vent system to any combination of control devices (excluding a flare); or

ii. Reduce total organic HAP emissions by venting emissions through a closed vent system to a flare; or

iii. Comply with the requirements in § 63.2450(e)(4), as applicable; and reduce total HAP emissions by venting emissions to a fuel gas system or process in accordance with § 63.982(d) and the requirements referenced therein. ¹

b. The maximum true vapor pressure of total HAP at the storage temperature is <76.6 kilopascals

i. Comply with the requirements of subpart WW of this part, except as specified in § 63.2470; or

ii. Reduce total HAP emissions by ≥95 percent by weight or to ≤20 ppmv of TOC or organic HAP and ≤20 ppmv of hydrogen halide and halogen HAP by venting emissions through a closed vent system to any combination of control devices (excluding a flare); or

iii. Reduce total organic HAP emissions by venting emissions through a closed vent system to a flare; or

iv. Comply with the requirements in § 63.2450(e)(4), as applicable; and reduce total HAP emissions by venting emissions to a fuel gas system or process in accordance with § 63.982(d) and the requirements referenced therein. ¹

2. Halogenated vent stream from a Group 1 storage tank

You use a combustion control device to control organic HAP emissions

Meet one of the emission limit options specified in Item 2.a.i or ii. in Table 1 to this subpart.

3. Storage tank of any capacity and vapor pressure

Beginning no later than the compliance dates specified in § 63.2445(i), the stored liquid contains ethylene oxide such that the storage tank is considered to be in ethylene oxide service as defined in § 63.2550

Comply with the applicable emission limits specified in items 1 and 2 of this Table, and also:

i. Reduce emissions of ethylene oxide by venting emissions through a closed-vent system to a flare; or

ii. Reduce emissions of ethylene oxide by venting emissions through a closed-vent system to a control device that reduces ethylene oxide by ≥99.9 percent by weight, or to a concentration <1 ppmv for each storage tank vent.