MACT emission limitation for new sources
Maximum achievable control technology (MACT) emission limitation for new sources means the emission limitation which is not less stringent than the emission limitation achieved in practice by the best controlled similar source, and which reflects the maximum degree of reduction in emissions of hazardous air pollutants (including a prohibition on such emissions, where achievable) that the Administrator, taking into consideration the cost of achieving such emission reduction, and any non-air quality health and environmental impacts and energy requirements, determines is achievable by sources in the category or subcategory to which such emission standard applies.
Source
40 CFR § 63.51
Scoping language
Terms used in 63.50 through 63.56 that are not defined in this section have the meaning given to them in the Act, or in subpart A of this part.