Scrubber – Suction system with hoods.
Fumes extraction is desirable on all etching and anodizing tanks as the hydrogen evolves during the processes and carries fine drops of caustic soda and sulphuric acid. The ducting is normally made of PVC or polypropylene, but stainless steel has also been used in some plants. Push-pull extraction systems are sometimes used. In most areas the fumes will require scrubbing in dilute acid/alkali or in water before being released into the atmosphere.