Dangers of Glass Etching Acid

Health Risks of Using Acid to Etch Glass

Where can I purchase hydrofluoric acid for etching glass? Thanks – and I love your site!

Milly’s answer: Thanks for giving me the opportunity to underline just how dangerous etching with hydrofluoric acid is! I ONLY use it in the dedicated fume cabinet at college – perhaps you could find an institution or studio near you that has a similar set up that you can hire? We buy it through a company that specialises in chemicals for laboratories. You may be asked rigorous questions about what you’re going to use it for, and how you’re going to dispose of it before they sell it to you. We have a safe disposal arrangement with the supplier. I’ve been meaning to add warnings to my Etching page, so here goes… they’re taken from various risk assessments and data sheets, and make for salutary reading – and may put you off for life! Please be extremely careful with this acid – it’s lethal:

Hydrofluoric Acid is an extremely corrosive material which attacks all tissues of the body. Contact with the skin results in deep tissue burns that are extremely slow to heal. Contact with dilute (<25%) HF solutions may not be felt until a few hours has past, resulting in major tissue damage. Skin contact with higher concentrations of HF causes immediate and painful burns as well as massive tissue and bone destruction.

Hydrofluoric Acid Toxicity penetrates the skin, destroys underlying tissues and attacks the bone. Solutions as weak as 1% will still rapidly permeate the skin and severely damage underlying tissues. Hydrofluoric Acid vapor burns the eyes, ultimately leading to blindness. At concentrations of 10 ppm to 15 ppm HF vapors begin to irritate the eyes. Brief exposure (5 min) to concentrations greater than or equal to 50 ppm can be fatal. Ingestion of HF leads to severe burns of mouth and throat. HF is not a human carcinogen. (At last – a positive!)

Store Hydrofluoric Acid in polyethylene bottles and in secondary containment.

Do not use glass! Take specific steps to store HF away from ammonia and other bases.

All work with HF should be done in an appropriately rated chemical fume hood.

Appropriate personal protective equipment must be worn i.e. safety glasses (or preferably a face shield), PVC or Neoprene gloves which are frequently and carefully checked for damage especially pin holes, a lab-coat and preferably a chemical proof apron.

Washing hands and gloves frequently with water is wise when working with even dilute HF.

Hydrofluoric acid is hazardous waste. Therefore it must be disposed according to specific procedures.