Texas Air Control Board Austin Texas Memorandum To: Permit Engineers From: Lawrence E. Pewitt, P. E., Director, Permits Program Date: April 25, 1991 Subject: Standard Exemption 106 Interpretation Recently, it has been pointed out that, if the exemption is interpreted literally, provision (d) completely obviates use of provision (c). The logic is that some of the chemicals in (c) have an L value less than 200 mg/m3 in which case (d) forbids their use. Similarly, for the other chemicals in (c) having no L values or values above 200 mg/m3, provision (d) allows 1 pound per hour only. Thus, provision (c) is useless. The original intent was to have (c) and (d) be independent requirements. The point of paragraph (c) was to allow the exemption of certain compounds even if they would otherwise not be exemptible under (d). We will certainly try to resolve this problem in a future exemption change. Your input on wording changes would be appreciated. In the meantime, please advise exemption claimants that provision (c) takes precedence over (d) to the extent of any conflicting statements. cc: James C. Myers, P.E., Deputy Director, Regulatory Operations Debra Barber, Director, Enforcement and Field Operations Program