How valid are your CoSHH risk assessments?
Published Date: 23rd March 2009
Chemicals are hazards. The degree of hazard depends upon their nature, i.e. their toxicity and other properties. However, in general terms any damage to health from a chemical can only occur if there is exposure.
So if a chemical is locked away in a suitable storage system which is not accessed by anyone, any risk of damage to health would be limited to an event such as a fire, or perhaps an earthquake, that might damage the storage and release the chemical.
Of course, most organisations will not usually purchase a chemical only to keep it locked away and never used. They purchase a chemical for a specific purpose, be it to lubricate, clean, glue objects together, seal, etc. It is when the chemical is used that the potential for exposure occurs. In other words, the risk arises out of the use, not out of the particular properties of the chemical. This is why exposure to water remains the most common cause of occupational contact dermatitis, i.e. as a result of what is termed “wet work”.
So risk assessment must be task based.
Merely collecting all the safety data sheets for substances purchased, then attempting to conduct a risk assessment safety data sheet by safety data sheet is not the correct approach. We need to start by identifying the task, then what chemicals are used in the execution of that task and how they are used. From this we can identify the hazard that will arise from the use of these chemicals.
Note that this may be very different from the original hazards of the chemicals as purchased. We may mix, dilute, react, heat or otherwise change the nature of the chemicals and the resultant hazard during the execution of the task.
Once we know the hazard then we can decide what the risk to the individual worker might be.
Or can we?
The reality is that it isn’t quite that simple. Take the most common form of occupational skin disease, irritant contact dermatitis. This can be defined as multifactorial and chronic. What does this mean? When skin is in contact with an irritant chemical some damage to the the skin will occur. All irritants will damage everyone’s skin to some extent, even if there is no visible indication of this. Once the contact has ceased, the skin, given time, can repair itself. However, if before the repair process has been completed that skin is again in contact with an irritant more damage will occur, again usually with no visible indication that this is happening. Repeated sufficiently often the damage will accumulate to a point where the skin can no longer withstand the assault. This is when the visible dermatitis appears.
Now consider that we have our skin for twenty-four hours each day, of which probably only eight are spent at work, and that there will be many irritants outside the workplace, e.g. in the home, to which that skin could be exposed. Consider also that the worker may carry out several different tasks, involving the skin being exposed to several different irritants. How does this affect the risk assessment?
When conducting a risk assessment for skin exposure only rarely can one consider a single chemical in isolation. It is the cumulative effect of repeated exposures to many different chemicals – not necessarily used in the task under assessment – that is often the most significant factor in any risk assessment for skin exposure to chemicals.
Furthermore, it is essential that the risk assessment is based on those chemicals that are actually present during the execution of the task. These may be very different from those purchased or present at the start of the task and may vary both during that actual task and with time.
Consider that degreasing tank, freshly filled with toluene. The tank only contains toluene until the first component is degreased. The content is now toluene plus the various substances that have been removed from the component. As more components are degreased not only will the concentration of different substances change, but possibly the list of substances themselves. This is particularly the case when cleaning items that, for example, have been returned by a customer for repair or refurbishment. Do we even know what is on that returned component?
So if our risk assessment is restricted to the toluene, how valid will it be?
This article was provided by Chris Packham of EnviroDerm Services (UK) Ltd. EnviroDerm are a specialist consultancy training provider in the fields of risk assessment, risk management, skin care and skin management. EnviroDerm have a wealth of knowledge and experience that cannot be matched anywhere else in the world.