I think there are two aspects you need to address. First, the knowledge base that indicates to you where to look for the problem. You need to know where products were used and be pretty knowledgeable, otherwise you are going to miss a lot of stuff. You must have noted in your normal work, that knowing where asbestos was frequently used is a great help in compiling registers. You don't go into a building without some idea of where to start looking. Second, if you are going to use any sampling to confirm your observations you are going to need some expertise ins sampling and identification. The identification will be specific to the substance.

One of the first things you will need to do is to define just what you are going to include as a 'hazardous chemical'. Almost an chemical can become a hazardous substance under certain circumstances. COSSH recognises this in its definitions. Any substance can become a hazard depending upon "its toxicological properties and the way it is used or is present at the workplace". There are many substances that have never been allocated a risk or safety phrase ( or now a hazard statement ) that, if exposure of the skin is sufficiently often and prolonged, can cause damage to health. Indeed water, not normally considered a hazardous substance, is actually the most common cause of occupational contact dermatitis. When carrying out a risk assessment for the potential for damage to health due to skin exposure I always start with the task and attempt to identify the chemical hazard from what chemicals are being used, what is happening to them during the task and what changes in the chemical(s) might be resulting. From this the hazard can be identified. So a catalogue of hazards based on, for example, safety data sheets can be very misleading. Chris