R 336.1230 Lists for toxic air contaminants health-based screening levels, emission rate reviews, and T-BACT determinations.

Rule 230. (1) The department shall maintain the following information and make it available on the department’s website: (a) Toxic air contaminant names and chemical abstract service numbers and the basis for determining each of the following screening levels: (i) Initial threshold screening levels reviewed by the department. (ii) Initial and secondary risk-based screening levels reviewed by the department. (iii) For paragraphs (i) and (ii) of this subdivision, the date of the screening level derivation, the algorithm used, the uncertainty factors used, a brief description of the best available information for the screening level, and citations for the key studies and information sources. (b) Ambient concentrations for toxic air contaminants reviewed by the department under R 336.1226(d) and R 336.1228, the applicable chemical abstract service number, and the basis for any alternative concentration approved under these rules. (c) T-BACT determinations reviewed by the department. (2) The department shall make available on the department’s website the initial established health-based screening levels for toxic air contaminants as follows: (a) Within 60 days of the effective date of this rule, the department shall provide notice of initial established health-based screening levels for toxic air contaminants and accept comments on the screening levels for a period of 60 days. (b) Within 180 days following the receipt of comments and full consideration thereof, the department shall finalize and publish the health-based screening levels together with a response to substantive comments received. (c) The initial established health-based screening levels shall remain applicable until the public review process described in this subrule is completed. (3) After the health-based screening levels are finalized under subrule (2) of this rule, the department may establish additions or changes to the health-based screening levels as follows: (a) Within 6 months of establishing any additions or changes to the screening levels, the department shall make available on the department’s website any established additions or changes to the screening levels and shall provide public notice of the action and accept comments for a period of 30 days. (b) Within 60 days following the receipt of comments and full consideration thereof, the department shall publish a final decision and a response to substantive comments received. (c) The additions or changes to the screening levels established by subrule (3) of this rule shall remain applicable until the public review process described in this subrule is completed.