Section 63.2993 - What test methods must I use in conducting performance tests?(a) Use EPA Method 1 ( 40 CFR part 60, appendix A-1) for selecting the sampling port location and the number of sampling ports.(b) Use EPA Method 2 ( 40 CFR part 60, appendix A-1) for measuring the volumetric flow rate of the stack gas.(c) Use EPA Method 3 or 3A ( 40 CFR part 60, appendix A-2) for measuring oxygen and carbon dioxide concentrations needed to correct formaldehyde concentration measurements to a standard basis.(d) Use EPA Method 4 ( 40 CFR part 60, appendix A-3) for measuring the moisture content of the stack gas.(e) Use EPA Method 316, 318, or 320 ( 40 CFR part 63, appendix A) for measuring the concentration of formaldehyde.(f) Use the method contained in appendix A to this subpart or the resin purchase specification and the vendor specification sheet for each resin lot for determining the free-formaldehyde content in the urea-formaldehyde resin.(g) Use the method in appendix B to this subpart for determining product loss-on-ignition.84 FR 6694, Feb. 28, 2019