This section applies beginning no later than the compliance dates specified in § 63.100(k)(11). To determine if process vents, storage vessels, equipment leaks, wastewater, and heat exchange systems are in ethylene oxide service, as defined in § 63.101, owners and operators must comply with the requirements in paragraphs (a) through (e) of this section, as applicable.

(a) Except as specified in paragraph (a)(7) of this section, for each Group 1 and Group 2 process vent stream, owners and operators must measure the flow rate and concentration of ethylene oxide of each process vent as specified in paragraphs (a)(1) through (6) of this section.

(1) Measurements must be made prior to any dilution of the vent streams.

(2) Measurements may be made on the combined vent streams at a chemical manufacturing process unit or for each separate vent stream.

(3) The sampling site shall be after the last recovery device (if any recovery devices are present) but prior to the inlet of any control device that is present and prior to release to the atmosphere. Method 1 or 1A of appendix A-1 to part 60 of this chapter, as appropriate, must be used for the selection of the sampling sites. For vents smaller than 0.10 meter in diameter, sample at one point at the center of the duct.

(4) The gas volumetric flow rate must be determined using Method 2, 2A, 2C, 2D, 2F, or 2G of appendices A-1 and A-2 to part 60 of this chapter (respectively), as appropriate.

(5) Except as specified in paragraph (a)(6) of this section, the concentration of ethylene oxide must be determined using Method 18 of appendix A-6 to part 60 of this chapter, or Method 320 of appendix A to this part.

(6) You may elect to use ASTM D6348-12 (Reapproved 2020) (incorporated by reference, § 63.14) in lieu of Method 320 of appendix A to this part as specified in paragraph (a)(5) of this section. To comply with this paragraph, annexes Al through A8 to ASTM D6348-12 (Reapproved 2020) are mandatory; the percent (%) R must be determined for each target analyte using Equation A5.5 of ASTM D6348-12 (Reapproved 2020) Annex A5 (Analyte Spiking Technique); and in order for the test data to be acceptable for a compound, the %R must be 70% ≥ R ≤ 130%. If the %R value does not meet this criterion for a target compound, then the test data is not acceptable for that compound and the test must be repeated for that analyte (i.e., the sampling and/or analytical procedure should be adjusted before a retest). The %R value for each compound must be reported in the test report, and all field measurements must be corrected with the calculated %R value for that compound by using the following equation:

Equation 1 to Paragraph (a)(6) Reported Results = (Measured Concentration in the Stack × 100)/%R.

(7) The requirements specified in paragraphs (a)(1) through (6) of this section for an initial measurement or initial performance test do not apply if the conditions specified in paragraphs (a)(7)(i) through (iv) of this section are met for a previously conducted measurement or performance test.

(i) No changes have been made to the process since the time of the measurement or performance test;

(ii) The operating conditions and test methods used during measurement or performance test conform to the ethylene oxide related requirements of this subpart;

(iii) The control device and process parameter values established during the previously conducted measurement or performance test are used to demonstrate continuous compliance with the ethylene oxide related requirements of this subpart; and

(iv) The previously conducted measurement or performance test was completed within the last 60 months.

(b) For storage vessels, owners and operators must determine the concentration of ethylene oxide of the fluid stored in the storage vessels by complying with the requirements in paragraph (b)(1) or (2) of this section.

(1) The owner or operator must measure concentration of ethylene oxide of the fluid stored in the storage vessel using Method 624.1 of appendix A to 40 CFR part 136, or preparation by Method SW-846-5031 or SW-846-5030B and analysis by Method SW-846-8260D (incorporated by reference, see § 63.14). The owner or operator may not use a preservative in the collected sample; the owner or operator must store the sample with minimal headspace as cold as possible and at least below 4 degrees C; and the owner or operator must analyze the sample as soon as possible, but in no case longer than 7 days from the time the sample was collected. If owners and operators collect a sample from a pressure vessel, then the owner or operator must maintain the sample under pressure both during and following sampling.

(2) Unless specified by the Administrator, the owner or operator may calculate the concentration of ethylene oxide of the fluid stored in the storage vessels if information specific to the fluid stored is available. Information specific to the fluid stored includes concentration data from safety data sheets.

(c) For equipment leaks, owners and operators must comply with the requirements in paragraphs (c)(1) through (4) of this section.

(1) Each piece of equipment within a chemical manufacturing process unit that can reasonably be expected to contain equipment in ethylene oxide service is presumed to be in ethylene oxide service unless the owner or operator demonstrates that the piece of equipment is not in ethylene oxide service. For a piece of equipment to be considered not in ethylene oxide service, it must be determined that the percent ethylene oxide content of the process fluid that is contained in or contacts equipment can be reasonably expected to not exceed 0.1 percent by weight on an annual average basis. For purposes of determining the percent ethylene oxide content of the process fluid, owners and operators must use Method 18 of appendix A-6 to part 60 of this chapter, for gaseous process fluid, and Method 624.1 of appendix A to part 136 of this chapter, or preparation by Method SW-846-5031 and analysis by Method SW-846-8260D (both incorporated by reference, see § 63.14) for liquid process fluid. In lieu of preparation by Method SW-846-5031, owners and operators may use Method SW-846-5030B (incorporated by reference, see § 63.14), as long as: the owner or operator does not use a preservative in the collected sample; the owner or operator stores the sample with minimal headspace as cold as possible and at least below 4 degrees C; and the owner or operator analyzes the sample as soon as possible, but in no case longer than 7 days from the time the sample was collected.

(2) Unless specified by the Administrator, owners and operators may use good engineering judgment rather than the procedures specified in paragraph (c)(1) of this section to determine that the percent ethylene oxide content of the process fluid that is contained in or contacts equipment does not exceed 0.1 percent by weight.

(3) Owners and operators may revise a determination for whether a piece of equipment is in ethylene oxide service by following the procedures in paragraph (c)(1) of this section, or by documenting that a change in the process or raw materials no longer causes the equipment to be in ethylene oxide service.

(4) Samples used in determining the ethylene oxide content must be representative of the process fluid that is contained in or contacts the equipment.

(d) For wastewater, owners and operators must determine the concentration of ethylene oxide of each wastewater stream using Method 624.1 of appendix A to part 136 of this chapter, or preparation by either Method SW-846-5031 or SW-846-5030B and analysis by Method SW-846-8260D (incorporated by reference, see § 63.14). The owner or operator may not use a preservative in the collected sample; the owner or operator must store the sample with minimal headspace as cold as possible and at least below 4 degrees C; and the owner or operator must analyze the sample as soon as possible, but in no case longer than 7 days from the time the sample was collected.

(e) For heat exchange systems, owners and operators must comply with the requirements in paragraph (e)(1) or (2) of this section.

(1) Determine the concentration of ethylene oxide of the process fluid cooled by the heat exchange system using Method 624.1 of appendix A to part 136 of this chapter, or preparation by either Method SW-846-5031 or SW-846-5030B and analysis by Method SW-846-8260D (incorporated by reference, see § 63.14). The owner or operator may not use a preservative in the collected sample; the owner or operator must store the sample with minimal headspace as cold as possible and at least below 4 degrees C; and the owner or operator must analyze the sample as soon as possible, but in no case longer than 7 days from the time the sample was collected. soon as possible, but in no case longer than 7 days from the time the sample was collected.

(2) Unless specified by the Administrator, owners and operators may use good engineering judgment rather than the procedures specified in paragraph (e)(1) of this section to determine that the percent ethylene oxide content of the process fluid cooled by the heat exchange system does not exceed 0.1 percent by weight.

[89 FR 43173, May 16, 2024]