Oxalic Acid

[stelmackr]

Occasionally I find a reference to the use of oxalic acid to prepare a finished leather carving for the dye and final finish. This causal reference needs a little additional comment as to the toxicity of the chemical. Oxalic acid can be absorbed through the skin and can cause internal damage. Here are some cautionary notes from the International Occupational Safety and Health Information Centre:

EXPOSURE

AVOID ALL CONTACT!

IN ALL CASES CONSULT A DOCTOR!

ROUTES OF EXPOSURE:

The substance can be absorbed into the body by inhalation of its aerosol and by ingestion.

INHALATION RISK:

Evaporation at 20°C is negligible; a harmful concentration of airborne particles can, however, be reached quickly if powdered.

EFFECTS OF SHORT-TERM EXPOSURE:

Corrosive. The substance is corrosive to the eyes, the skin and the respiratory tract. Corrosive on ingestion. Inhalation of aerosol may cause lung oedema. The substance may cause effects on the kidneys. Exposure far above the OEL may result in death. Medical observation is indicated.

EFFECTS OF LONG-TERM OR REPEATED EXPOSURE:

Repeated or prolonged contact with skin may cause dermatitis. The substance may have effects on the kidneys , resulting in stones.

I might suggest those Nitrile Disposable Gloves from Harbor Freight which are better at resisting chemicals than the more common Latex Disposable Gloves. And just be careful: eye protection, long sleeved shirts, etc.

Bob Stelmack