Obvious: EPA can produce the data to justify their rules and regulations under the Clean Air Act.

If the data can not be shared and the results repoduced buy other, it's not science. Anthropogenis global warming has the same problem.

(CNSNews.com) – Seven months after being subpoenaed by Congress, Environmental Protection Agency (EPA) Administrator Gina McCarthy conceded that her agency does not have - and cannot produce - all of the scientific data used for decades to justify numerous rules and regulations under the Clean Air Act.
In a March 7th letter to House Science, Space and Technology Committee chairman Lamar Smith (R-Tex.), McCarthy admitted that EPA cannot produce all of the original data from the 1993 Harvard Six Cities Study (HSC) and the American Cancer Society’s (ACS) 1995 Cancer Prevention Study II, which is currently housed at New York University.[...]
The full committee, which issued its first subpoena in 21 years last August after being stonewalled by the EPA for two years, wanted the raw data from the studies so that their results could be replicated by independent researchers. (See EPA subpoena.pdf)
However, despite “multiple interactions with the third party owners of the research data in an effort to obtain that data,” McCathy wrote, some of the data subpoenaed by the committee “are not (and were not) in the possession, custody or control of the EPA, nor are they within the authority to obtain data that the agency identified.”
“EPA has not withheld any data in our possession that is responsive to the subpoena,” McCarthy stated. “The EPA acknowledges, however, that the data provided are not sufficient in themselves to replicate the analyses in the epidemiological studies, nor would they allow for the one to one mapping of each pollutant and ecological variable to each subject.” (See EPA letter to Smith March 7 2014 (1).pdf)