Safety data sheets – help or hazard?
June 1st 2008

Safety data sheets, as provided by manufacturers, can be a useful reference source for employers, but EnviroDerm's Chris Packham urges caution against using them as a sole source of advice

Probably the majority of risk assessments for chemicals in the workplace produced in order to comply with COSHH are based on the information contained in the relevant safety data sheets. Probably many of these are also wrong. The reason? Safety data sheets are sometimes found to be incorrect and are not produced for COSHH but for CHIP.

In other words, safety data sheets are only relevant for the chemical 'as supplied', whereas what the employer actually needs is information on the product 'as used'. In a large number of cases, the information required is not to be found in the safety data sheet.

A case in point was a factory where a pre-impregnated carbon fibre sheet was being used to produce aircraft components. The safety data sheet showed that this contained a potent sensitiser at a high concentration (>60%). A claim had been made that this had caused an allergic contact dermatitis. Investigation showed that the sensitiser was so tightly bound into the mat that not enough was being released to cause any skin problem.

In a metalworking company a worker had become sensitised to the biocide in the water-mixed metalworking fluid. This was formaldehyde. Accordingly the company requested their supplier to provide a metalworking fluid that did not contain this sensitiser. This request was complied with and the new fluid put into the worker's machine. The company expected that the dermatitis would now disappear. Instead it became steadily worse. I was requested to investigate.

A quick glance at the safety data sheet for the new fluid revealed that, while as supplied there was no formaldehyde, the product included a biocide known as a "formaldehyde releaser". In use formaldehyde was accumulating as the biocide degraded and the worker was continuing to be exposed.

In fact, the provision of information about safe use of any chemical is covered in the original Health and Safety at Work etc. Act 1974. Section 6-1 includes the following requirement on the part of the supplier: It shall be the duty of any person who designs, manufactures, imports or supplies any article for use at work: (c) to take such steps as are necessary to secure that there will be available in connection with the use of the article at work adequate information about the use for which it is designed and has been tested, and about any conditions necessary to ensure that, when put to that use, it will be safe and without risks to health.

This is quite a different requirement than that for the safety data sheet. It means that the supplier must either state, or know, what the use will be and be able to provide the relevant information. Not all suppliers do this, and in many cases seem unaware that this is part of their legal obligations.

A further complication arises when products that will be used together are purchased from different suppliers.

Mixing these may well produce other substances that are not on either safety data sheet and that may represent new, and potentially significant hazards. Which supplier is legally responsible for providing the information on a mixture, of which one or more constituents were not supplied by him, is not clear. Experience indicates that if both suppliers are contacted and provide their understanding of the hazard, the information that each provides may well not be compatible with that from the other.

Accuracy is another problem. The author recently conducted a dermal exposure audit in a large printing works. In one area safety data sheets on seven chemicals were reviewed. Every one recommended a particular type of glove, but every recommendation was actually wrong. In one study, presented at an international conference on skin in Sweden in 2005 Dr. Rosemary Nixon and her colleagues reported that: "Non-compliant MSDS may have been as high as 42%".

So when conducting a risk assessment for chemical exposure it would be prudent firstly to contact suppliers, informing them of the process in which their product will be used and requesting that they provide the relevant information. Once all the relevant information for the task being assessed has been obtained, then this should be collated to ensure that all the different information is compatible. At least then the risk assessment will be based on valid hazard data.

Finally, from the above it should be clear that a risk assessment, at least for skin exposure, cannot be done by relying upon risk phrases. In fact, paragraph 13 of the Approved Code of Practice for COSHH covers this, stating: Many commonly supplied substances...are listed in Part I of the Approved Supply List: Information approved for the classification and labelling of substances and preparations dangerous for supply. However, that document should not be regarded as a complete listing of chemicals covered by COSHH as it deals only with substances subject to CHIP and even then omits many substances and all preparations.

Ultimately REACH should improve the situation as all substance manufacturers will have to supply Exposure Scenarios for each use to which their substance may be put, possibly as a substance or, more probably, in a preparation.

How well this will work in practice remains to be seen.

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