N.M. Code R. § 20.2.72.400
The Board is concerned about the increasingly common presence of toxic air pollutants in the ambient air. The Board believes that the best approach to regulating sources of toxic air pollutants over the long term is to set ambient standards for each pollutant of concern. However, because of financial constraints, the unavailability of sufficient information to establish such ambient standards, the time necessary to establish such standards for the contaminants identified as toxic air pollutants and because the Board wishes to implement a toxic air pollutant permitting program as soon as possible, the Board has adopted a source-by-source permit-based approach for the present. Under this permit-based approach, the Board has given limited authority to the Department to use factors of the OELs (occupational exposure limits) in evaluating permit applications. The Board recognizes that the use of OELs, or factors of them, as ambient air standards would be inappropriate; therefore, the Board has authorized their use for screening purposes only. This authorization is not intended to represent, and should not be interpreted as, a finding by the Board that these factors are suitable for determining safe or unsafe ambient air concentrations. Various respected groups, such as the American Conference of Governmental Industrial Hygienists (ACGIH), may develop ambient air exposure guidelines in the future. Development of ambient air guidelines by groups such as this could be the basis for developing toxic air pollutant ambient air standards. The Board also notes that the Department currently is developing an emissions inventory of toxic air pollutants. An emissions inventory may identify toxic air pollutants that are of particular concern in New Mexico. The Board believes that efforts like these may facilitate the development of toxic air pollutant ambient air standards. For these reasons, the Board requests the Department to prepare and present a report to the Board within five years of the effective date of the toxic air pollutant permitting requirements. The report shall review and evaluate the implementation of the toxic air pollutant permitting program, summarize the results of the toxic air pollutant inventory gathered pursuant to AQCR 752, and review scientific and technical progress made in the area of toxic air pollutants that might facilitate the development of toxic air pollutant ambient air standards. The Board shall schedule a discussion of this report at a regular monthly meeting within three months of the publication of this report.
N.M. Code R. § 20.2.72.400