Refrigeration systems, including storage tanks used in refrigeration systems, that use one of the following categories of refrigerant are permitted by rule:
(1) simple asphyxiants limited to argon, carbon dioxide, ethane, helium, hydrogen, methane, neon, nitrogen, propane, propylene, or liquefied natural gas; or
(2) any other chemical, excluding anhydrous ammonia, with a short-term effects screening level (ESL) published in the commission's ESL list greater than 150 µg/m 3 ;
(3) anhydrous ammonia (ammonia) provided:
Source Note: The provisions of this §106.373 adopted to be effective March 14, 1997, 22 TexReg 2439; amended to be effective July 8, 1998, 23 TexReg 6966; amended to be effective September 4, 2000, 25 TexReg 8653