Copper dusts and mists

The American Conference of Governmental Industrial Hygienists threshold limit value time-weighted average is 0.2 mg m for copper fume and 1 mg m for copper dusts and mists. 

Note Also see specific listing for Copper (dusts and mists) ] ... 

COPPER DUST AND MIST (AS CU) Cu Synonyms vary depemfing upon specifk compound Acetylene gas, magnesium metal y... 

Inhalation of dusts can cause metal fume fever (79,80), and ulceration or perforation of the nasal septum. Mild discomfort has been noted with workplace concentrations as low as 0.08 mg/m. The workplace standard (TLV) for copper dusts or mist is 1 mg/m and 0.2 mg/m for copper fume (81). 

A. Inhalation. The recommended workplace limit (ACGIH TLV-TWA) for copper fumes is 0.2 mg/m for dusts and mists, it is 1 mg/m. The air level considered immediately dangerous to life or health for dusts or fumes is 100 mg Cu/m. ... 

Copper fumes, dusts, and salts Irritation upon direct contact varies with the ccmpcund, The salts are more irritating and can cause corneal ulceration, Allergic contact dermatitis is rare. Dusts and mists irritating to the respiratory tract nasal ulceration has been desoribed. Ingestion can cause severe gastroenteritis and hepatio injury. See also p 175. 0.2 mg/m (fume) 1 mg/m (dust and mists) 100 mg/m (as Cu) Salts vary in color. Generally odoriess. 

Copper like vanadium has a separate OSHA standard for dust and fumes resulting in some confusion for the industrial hygienist in selecting collection media. The 0.2 mg Cu/cu m fume standard is one-fifth the dust standard. The distinction between fumes and mist is somewhat ambiguous. Both methods for copper use nitric acid wet ashing however, S-186 uses an analyte matrix of hydrochloric acid for AAS aspiration. 

Electrostatic Mist Precipitators. The gas leaving the scrubbers is essentially free of halogens and dust but it still contains acid mist. The amount of acid mist depends primarily on conditions in the smelter. In gas from copper converters, the sulfur trioxide content may vary from 2 to 10% of the total sulfur oxides. The amount of sulfur trioxide formed depends largely on the temperature and time the gas contacts the iron oxide in the dust and the scale on the carbon steel flues. The sulfur trioxide combines with the moisture in the gas to form sulfuric acid vapor. When the gas is cooled in the scrubbers, most of this vapor condenses as a finely divided acid mist, although some of it is absorbed in the scrubber liquor. Sulfuric acid mist, which is generally considered to be particles less than 5 is very difficult to remove from a gas stream, so only a portion of the mist will be removed in the scrubber. If the remaining mist were allowed to enter the contact section of the acid plant it would corrode the carbon steel ducts and heat exchangers and the main blower. It must, therefore, be removed as completely as possible in the purification section of the plant. This is accomplished in the electrostatic mist precipitators. 

Although the toxicity of metallic copper is very low, many copper(II) salts may have varying degrees of toxicity. Inhalation of dusts, mists or fumes of the metal can cause nasal perforation, cough, dry throat, muscle ache, chills and metal fever. Copper in trace amounts is a nutritional requirement, used metaholically in plant and animal enzymes and other biological molecules. It can be either a toxicant or a nutrient within a concentration that may be in the same order of magnitude. 

Beryllium and its alloys (e.g., beryllium copper) have gained interest in the aerospace industry and specialty sports equipment industry in recent years. Brazing or riveting can be used for joining, but these methods are expensive, and distortion or highly stressed areas may be encountered. The metal must be handled with care when the processing produces dust, chips, scale, slivers, mists, or fumes, since airborne particles of beryllium and beryllium oxide are toxic with latent health effects. Abrasives and chemicals used with beryllium must be disposed of properly. 

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