Air Sample Analysis for Acid Mist
Acid mist is a by-product that can occur during mining operations for copper and other metals. It can be produced during electrowinning which is a process to extract copper. The acid mist can invade the indoor air supply of the mine shaft or other areas causing harm to the respiratory system and skin. It can also cause damage to the actual tankhouse structures for the electrowinning procedure, risking further dangers to employees at the site.
Four common acids linked to acid mist in the workplace are:
Hydrogen Bromide – which is used in the manufacturing process of organic and inorganic bromides or as a reducing agent. It is a colourless, corrosive non-flammable gas, its fumes forming clouds than can cause a sour taste.
Nitric acid- which is used as a fertilizer and in the manufacturing of explosives. It is widely used including metal etching, or stainless-steel pickling. Nitric acid produces fumes in moist air and has a strong choking odour.
Phosphoric acid – used in a variety of processes such as rustproofing, engraving, coagulation of rubber latex, fertilizer, or the manufacture of pharmaceuticals. It is a dense colourless liquid and a strong irritant to tissue.
Sulphuric acid – is widely used in the manufacturing industry making paper, water purification, making phosphoric acid, rayon dyes, detergents and water purification amongst others. It is a dense oily liquid, corrosive and a strong irritant to tissue.
MSSL provides analysis for inorganic acid mist by Ion chromatography. Samples are collected in accordance with either OSHA Method ID-165SG, NIOSH 7903 or the ASTM D7773-12 method.
H2SO4, H3PO4 and other particulates are collected on the glass fiber plug while HBr and HNO3 are collected on the silica gel sorbant.
MSSL is able to assist with specification of the most appropriate method relative to the situation.