30 Tex. Admin. Code § 25.4
(a) An environmental testing laboratory must be accredited according to this chapter, except as provided in §25.6 of this title (relating to Conditions Under Which the Commission May Accept Analytical Data), if the laboratory provides analytical data which is used for a commission decision relating to a:
(b) An in-house environmental testing laboratory is to be accredited if it provides analytical data to a third party and the data is used for a commission decision relating to a:
(d) An environmental testing laboratory that provides analytical data used for a commission decision relating to the Safe Drinking Water Act must be:
Source Note:The provisions of this §25.4 adopted to be effective September 12, 2002, 27 TexReg 8480; amended to be effective October 7, 2010, 35 TexReg 8930.