Exposure Assessment: Hydrochloric Acid
Union staff requested an exposure assessment during routine chemical cleaning of lavatory drain lines using Calci-Solv (active ingredient: hydrochloric, or [syn.] muriatic acid). Exposure monitoring revealed variable concentrations of HCl exposure for seven different locations in the facility, however most were above the "ceiling" limit established by OSHA. In some instances, the airborne acid concentration approached the IDLH level for short periods.
Method: Dr�ger 1/a and 50/a short-term indicating tubes
Occupational Exposure Limits and Hygienic Values (1999): Hydrochloric Acid (syn. Muriatic Acid):
TEST 1 - 3-17-99 1000 Men's room Union Basement WB11 - 2 Urinals, no fan. Vent over urinals. 16 oz Calci-solve per trap. Trap vacuumed out before treatment. 12 ppm TEST 2 - 3-17-99 1030 Men's room Union Basement WB11 - Remaining 3 Urinals, with auxiliary (EHSRM fan at low rpm) fan on. Vent over urinals. 16 oz Calci-solve per trap. Trap vacuumed out before treatment. 16-20 ppm. Flushes turned off for about 1 hour after treatment. TEST 3 - 3-17-99 1345 Men's room Union W209 - 4 Urinals, no fan. 8 oz Calci-solve per trap. Trap not vacuumed out before treatment. 4 ppm. Flushes only shut off for 5-10 minutes after treatment. Some fuming still seen. TEST 4 - same as TEST 3, 10 minutes later. 0 ppm. TEST 5 - 3-17-99 1215 Men's room Union Basement WB11 - (1.45 hours after last treatment) 0 ppm. [TEST 6 - 3-17-99 1400 QC test of 0 ppm tubes using concentrated product - definitely a positive response. The entire tube discolors almost instantly.] TEST 7 - 3-17-99 1430 (est.) Men's room Union W125 - no fan. 8 oz Calci-solve per trap. Trap not vacuumed out before treatment. Very foamy. After 5 urinals - 10 ppm. [50 ppm at a sampling point very close to source.] W125 continued on other side. 2 Urinals. 8 oz. Calci-solve per trap. Trap not vacuumed out before treatment. No monitoring. TEST 8 - 3-17-99 1445 (est.) Men's room Union E261 - no fan. 8 oz Calci-solve per trap. Trap not vacuumed out before treatment. 1/8" Debris and sludge. 2 urinals - 0 ppm, 5-10 minutes after pouring product.
Observations / Questions / Comments:
Updated November 16, 2007