Hydrochloric Acid and Stainless Steel

[Twisted Brick]

Your basic toilet bowl cleaner will quickly dissolve minerals from stainless, but may require a little bit of scrubbing. Afterwards a thorough cleaning would be wise. Some of those thicker, gel toilet bowl cleaners that smell like bleach can be more mildly acidic and take longer to work.

This message was posted earlier and for safety reasons I feel it needs to be corrected. Not for the potential personal health hazards inherent in working with hydrochloric acid but because of the severe damage hydrochloric acid causes to stainless steel. From mash vessels to (conical) fermenters, boilers and storage vessels, the use of stainless is pervasive throughout our hobby.

From brief reading on the effects of hydrochloric acid on stainless steel, even a short contact period can cause irreversible damage including cracking, corrosion and pitting. Worse, it is also reported that the chemical reaction hydrochloric acid causes on contact with stainless steel compromises its ability to be later welded.

Metals such as aluminum, cast iron, steel, copper, and titanium will suffer rapid attack from HCl at all concentrations and temperatures. Most stainless steel grades will be subject to attack, because their chromium content is not sufficient in forming a protective passive layer.

A look into popular household toilet bowl cleaners revealed that virtually all use hydrochloric acid, and a random look found that one of the leading products, Lysol Brand contains 10-30% hydrochloric acid. From the above, it should be interpreted to avoid using toilet bowl cleaners on your ss vessels.

Lysol MSDS

Lysol Product Sheet

Hydrochloric Acid on Stainless Steel

If any member can report that these warnings and MSDS are inaccurate, please share what you know.