Equipment using aqueous solutions is permitted by rule, providing the conditions of this section are met.     
       (1) This section authorizes the following operations:                (A) anodizing, chromate conversion coating processes, electroplating, electrodeposition, electroless plating, electrolytic polishing, and electrolytic stripping, as follows.                    (i) For plating onto or stripping from any basis substrate, only brass, bronze, cadmium, copper, iron, lead, nickel, tin, zinc, and precious metals may be used.                     (ii) Chromic acid shall not be used in any step of a process which involves electrical current, air agitation, or any other factor which causes the chromic acid to bubble or mist.                   (B) cleaning, electroless stripping, etching, or other surface preparation and finishing, not including chemical milling or electrolytic metal recovery and reclaiming systems.        
       (2) Operating conditions.                (A) Hydrochloric acid tank operating conditions shall not exceed:                    (i) a temperature of 100 degrees Fahrenheit and a hydrochloric acid concentration of 19.0% by solution weight; or                     (ii) a partial pressure of 0.5 millimeters of mercury.                   (B) Hydrochloric acid in any state, and any aqueous solution which bubbles or mists due to electrical current, air agitation, or any other factor shall be used in an enclosed building. If the doors and windows of the building are open for any reason other than temporarily for access, emissions shall either be:                    (i) captured and exhausted using forced air through a stack with an unobstructed minimum vertical discharge of four feet above the peak of the roofline; or                     (ii) controlled with a fume suppressant.          
       (3) If a facility cannot comply with the hydrochloric acid temperature and concentration limits in paragraph (2)(A)(i) of this section, then to demonstrate compliance with paragraph (2)(A)(ii) of this section, the maximum hydrochloric acid temperature and concentration for each tank shall be recorded daily. At least once per month, the recorded data shall be converted to partial pressure. All data shall be maintained for the most recent 24-month period.      
     Source Note:        The provisions of this §106.375 adopted to be effective August 4, 1998, 23 TexReg 7830; amended to be effective September 4, 2000, 25 TexReg 8653