CONCENTRATED ACID SOLUTIONS

STANDARD OPERATING PROCEDURE:

Date: April 9, 1996

Issuer: John Barker, Safety Representative for Div. 856

• Normal Working Hours
  

  Work is to be done only during normal working hours (8 AM - 6 PM), or in the direct presence of a coworker in the lab.

• Label Work Area

  Label hood area where etchant is to be used with name, and date of etching.

• Protective Clothing

  Rubber gloves, lab coat, safety goggles, and rubber apron must be worn.

• Etching Containers

  Only glass containers with covers are to be used. Etchant should never be left uncovered.

• Cleanup of Work Area

  Etchant container and other contaminated equipment must be neutralized by a suitable buffered solution (excess baking soda in water). Note that concentrated acid will foam vigorously in such a solution, possibly splattering acid. Do not neutralize strong acids, expect with absolutely necessary. Dilute strong acids by adding at least 10 times excess water. Mix in buffer solution slowly, to minimize foaming. The fume hood work area must be neutralized with buffered solution after each use.

• Waste Products

  After finishing etching for the day, etchant solution is to be stored in glass containers with an outer plastic cover to limit breakage. The container's screw cap should be slightly loose to allow release of evolved gasses. Label container with hazard label indicating composition of waste, owner (yourself), and date. Dilute acids can be neutralized with buffered solution, and poured down the sink only after verifying with PH paper that PH is between 6-8.

• Neutralization of Spilled Acid

  Minor acid spills can be neutralized with buffered solutions of baking soda. Note that using excess baking soda assures that PH is neutral. Major acid spills should be treated as an accident, in which the Fire Protection Service should be called immediately at x2222. Acid spill absorbent is also located in the labs.

Last modified 02-April-2002