Corrosive perspiration

Brass door knob with evidence of crystal structure etched by corrosive perspiration. (Courtesy of Kingston Technical Software)... 

The temperature and humidity should be maintained at comfort conditions consistent with the operator s expected level of activity in order to minimise perspiration. Constant temperature and humidity may also be required in machine rooms to prevent the etching or corrosion of machine parts. If perspiration causes only minor damage to the product and results in few rejects, then inside design conditions at 27°C and 40% rh are satisfactory. Where even small amounts of perspiration cause extreme damage to precision-machined parts and result in a high amount of rejects, inside design conditions of 21°C and 40% rh are recommended. 

Workers exposed to an airborne fluoride concentration of 5mg/m complained of eye and respiratory tract irritation and nausea. The lethal oral dose of sodium fluoride for humans has been estimated to be 32-65 mg F/kg of body weight. Effects from ingestion are diffuse abdominal pain, diarrhea, and vomiting excessive salivation, thirst, and perspiration painful spasms of the limbs and sometimes albuminuria." Gastrointestinal effects produced after the acute ingestion of toxic amounts of fluoride likely arise from the corrosive action of hydrofluoric acid, which is produced within the acidic environment of the stomach. Cardiac arrest after accidental exposure to high levels of fluoride has been attributed to the development of hypocalcemia and/or hyperkalemia. ... 

All these form corrosive dusts those from water-soluble chromates are particularly dangerous since they dissolve in nasal fluid and in perspiration. Long-term exposure can lead to ulceration and cancer. Chromium trioxide may cause sensitisation by skin contact. 

Beuerlein, P. (1941). Die Korrosion der Metall dutch Handschweiss und ihre Ver-hiitung (The corrosion of metal by hand perspiration and its prevention). Werkstatt Betrieb, 74, 23-25 (in German). 

Oelsner, G. (1957). Korrosion metallLscher Oberflachen durch Handschweiss (Corrosion of metallic surfaces by hand perspiration). Jahrb. Oberflachentechn., 13, 49-58 (in German). 

Oelsner, G. (1959). Die Handschweisskoirosion metallischer Obetflachen (Hand perspiration corrosion of metallic surfaces). Galvanotechnik, 50, 77-84 (in German). 

Corrosive. Small splashes cause a local freezing effect. Liquid flooding causes burns affecting the entire exposed area. Ammonia vapor can dissolve in perspiration causing irritation and redness of the skin, depending on the vapor concentration and exposure. 

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