Mercaptoacetic acid

This chemical standard operating procedure (SOP) is for your safety. Read, understand, and follow this document. If this is a paper copy, you should check for the most recent version on the IsoLab website. This document was created from a template modeled after the University of Washington Environmental Health and Safety Laboratory Safety Manual Standard Operating Procedures Components.

Is Mercaptoacetic acid a particularly hazardous substance? YES

What is a particularly hazardous substance? The University of Washington Environmental Health and Safety defines it here.

The SDS for mercaptoacetic acid can be found here.

1. Process Mercaptoacetic acid (or Thioglycolic acid) is used to make the resin for selectively extracting selenium from solutions for later isotopic analyses.
2. Hazards Mercaptoacetic acid (or Thioglycolic acid) is toxic if swallowed or in contact with skin, causes severe skin burns and eye damage, causes serious eye damage, and harmful to aquatic life. Refer to the SDS for more information.
3. Personal Protective Equipment While working with mercaptoacetic acid in a fume hood you should be wearing nitrile gloves, a lab coats, and eye protection. Do not work with mercaptoacetic acid outside of the fume hood.
4. Environmental / Ventilation Controls Mercaptoacetic acid is to be used in one of the fume hoods in the 302 / 303 suite. Ensure the fume hood has appropriate flow prior to working with mercaptoacetic acid. Do not work with mercaptoacetic acid unless the fume hood is functioning properly.
5. Special Handling Procedures & Storage Requirements Mercaptoacetic acid is stored in the benchtop refrigerator in 303B. Make sure you have your laboratory coat, eye protection, and gloves on before handling the bottle.
6. Spill and Accident Procedures

Personal precautions, protective equipment and emergency procedures - Wear respiratory protection. Avoid breathing vapours, mist or gas. Ensure adequate ventilation. Evacuate personnel to safe areas.

Environmental precautions - Prevent further leakage or spillage if safe to do so. Do not let product enter drains. Discharge into the environment must be avoided.

Methods and materials for containment and cleaning up - Soak up with inert absorbent material and dispose of as hazardous waste. Keep in suitable, closed containers for disposal.

7. Waste Disposal

All mercaptoacetic acid waste is contained in an appropriate labeled tightly sealable plastic, wide-mouth, container. Do not open the waste container unless it is contained in a fume hood. Contact EH&S for waste removal when the container is sufficiently full or aged.

8. Special Precautions for Animal Use (if applicable) N/A
Particularly hazardous substance involved? YES, see 9-11
9. Approval Required

You must have taken Managing Laboratory Chemicals or similar UW EH&S condoned course before using mercaptoacetic acid. You must have read and understood the SDS for Mercaptoacetic acid as well as this SOP. You also must review your process with previously trained laboratory personnel.

10. Decontamination Any glassware that has been used with mercaptoacetic acid should be rinsed such that the first rinse goes into the above mentioned waste container. Subsequent rinse or washing of glassware can be done outside the fume hood in the sink as per normal lab glassware cleaning procedures.
11. Designated Area Mercaptoacetic acid may only be used in a fume hood. Preferably the fume hood directly above its storage location.


I have read and understood this Chemical SOP:

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Last updated: 2020-10-13 11:31:39