Text For Citation: 01 Item/Group: 001 Hazard: CHEMICAL

Section 5(a)(1) of the Occupational Safety and Health Act of 1970: The employer did not furnish employment and a place of employment which were free from recognized hazards that were causing or likely to cause death or serious physical harm to employees in that employees were exposed to incompatible chemical mixing: a)Wet Process Chemical Room - Incompatible chemicals, acids, bases, and a strong oxidizer were mixed in the common drain line for the dip tanks and at the waste sump in the southwest corner of the room. The acids were nitric acid and hydrofluoric acid; the bases were potassium hydroxide and ammonium hydroxide (an ammonia source); the strong oxidizer was hydrogen peroxide. b)Wet Process Chemical Room - An employee transferred acids and bases through the common chemical tank drain line to the waste sump in order to neutralize the containment tank. Incompatible chemicals, acids and bases, were being mixed. c)Wet Process Chemical Room, rinse tanks - Incompatible chemicals from the rinse tanks (DI tanks) were dumped to the common drain line and waste sump. Reactions of incompatible chemicals occurred. On one occasion an acid rinse tank containing nitric acid was dumped, followed by the dumping of a rinse tank containing potassium hydroxide. A "red smoke" appeared at the waste sump in the corner of the room. The "red smoke" was likely nitrogen dioxide from the decomposition of nitric acid. (It was not totally clear what caused this reaction.) The Merk Index calls nitrogen dioxide a "deadly poison". The IDLH (Immediately Dangerous to Life or Health) level is 20 ppm. 200 ppm may be fatal, even for a short exposure. d)Wet Process Chemical Room - Titanium depositions had been treated with Nitric Acid in the chemical cleaning process, which could have caused an explosion. Feasible controls included: 1.Have separate drain lines, sumps, and storage tanks for incompatible chemicals. 2.Flush the drain line and sump before dumping a rinse bath or the left over chemical from pumping a chemical tank to the waste barrels. 3.Stop the practice described in item b) above. 4.Provide a closed, ventilated system for the drain line and the sump. 5.Neutralize acidic and basic rinse tanks before they are dumped. 6.For instance d) develop a different chemical cleaning process.