Expert: Henry Boyter - 5/22/2006

Question
I am a newspaper. We had two men die in a well. All that is
known is that they put muriatic acid in the well and then water.
The second man was going in after the first one who had
collapsed and was seen to collapse as soon as his head got
below ground level (The well pit was 9 feet deep)

The question is could the acid have taken the oxygen out of the
air? Or was there another possible chemical reaction with the
muriatic acid that might explain what could have occured?

Answer
It could have been lack of O2, the HCl (muriatic acid) itself, or less likely the HCl could have reacted to produce Cl2 gas.

http://www.cdc.gov/niosh/idlh/intridl4.html

http://www.ucc.ie/academic/chem/dolchem/html/comp/hcl.html

All of this is covered in the OSHA confined space standard, although the procedure they did is not something that you normally would do to a well.  Muriatic acid should not be used this way.  It sounds like they didn't know what they were doing.

You should speak to an industrial hygiene firm in your area that may have more details of the incident than you provided.

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