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Risk of Handling and Cleaning Cadmium Plated Components

October 25, 2011

Hello there.
My company is concerned with the re-furbishment and maintenance of various components on sea going vessels, one component of which also contains numbers of Cadmium plated aluminium fasteners. The manager of the section involved has asked me for advice on the potential risk to the operators in handling and/or cleaning of these components. We work in a marine defence related industry and the fasteners cannot be replaced by another material without excessive cost and other contractual issues. Can any of your specialists offer any advice on corrosion mechanisms of these plated fasteners in a sea-water environment, with regard to potential toxicity to operators and maintenance personnel.
I don't yet have any information from the design authority on which specification these items have been plated to, but I imagine it would to a high quality, with a sealer.
Also, any alternative strategies offered would be welcome.

Martin Rich
Consultant - Plymouth United Kingdom

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Hi Martin,

It really depends on what you are planning to do with your cleaning operations and the condition of the plating.

Cadmium metal is a cumulative poison when absorbed or ingested, salts of cadmium have varying levels of toxicity, but cadmium oxide and cadmium chloride (the ones you'd expect to see is there is any corrosion of the cadmium) are both toxic in their own right.

If you are planning any form of mechanical cleaning loose particles will be dislodged and will give the potential for ingestion/inhalation of toxic substances. Added to the hazard of the cadmium I suspect these parts will have been passivated using a hexavalent chromium compound such as sodium dichromate. This has its own health implications as it is classified as a CMR.

Whatever you do around these fasteners you need to ensure that the operators are protected against exposure to either cadmium, cadmium salts or hexavalent chromium. Avoid any mechanical cleaning where possible. Where mechanical cleaning is necessary make sure full PPE is worn, including as a minimum impervious gloves, overalls and dust masks.

Try to stick to wet methods of cleaning if possible, aqueous cleaning would be preferable, sprayable cleaners would be best as this will help avoid exposure to hazardous materials. Have a chat with some of the chemical suppliers about appropriate cleaners to use (you can try the likes of Chemetall, Macdermid, Atotech, Applied Chemicals, etc...), they will all probably have experts able to help in your particular situation.

Brian Terry
Aerospace - Yeovil, Somerset, UK
October 31, 2011