Occupational dermatitis accounts for more than half of all occupational disease while one third of all rashes in a workforce are caused by the workplace.

Understandably, dermatitis frequently leads to litigation. Thirty-eight people were forced to leave work in the state in 1996 due to occupational dermatitis. (Dermatitis is synonymous with eczema.) There were 63 reported cases in 1995 and 44 in 1994.

But these are merely reported cases. And only include those whose skin complaints became so chronic that they had to give up work.

Dr Dan Murphy, medical director of the Health and Safety Authority, says the number forced to leave work due to dermatitis could be higher: "Many go to their own GP and we never hear about it." As many as 6 per cent of workers in the EU suffer from work-related skin problems, according to last year's survey by the European Foundation for the Improvement of Living and Working Conditions.

That figure rises to 10 per cent in the construction, electricity, gas and water sectors; 8 per cent in mining and manufacturing; and 7 per cent in agriculture, hunting, forestry and fishing. Employers and managers are required by law to inform workers about occupational dermatitis and to put in place mechanisms to prevent it.

There are two basic kinds of dermatitis. Irritant contact dermatitis and allergic contact dermatitis which is more likely to lead to litigation.

Irritant contact dermatitis is caused by exposure of the skin to irritant substances like cement or shampoo. If exposure continues, the initial chapping or dryness of the skin will lead to dermatitis. This in turn can lead to the more serious allergic contact dermatitis. For instance, a construction worker with an irritant reaction to cement could go on to develop allergic dermatitis due to chromate in cement.

Apprentice hairdressers develop irritant contact dermatitis more than experienced stylists because the novice does more shampooing. But construction workers are more likely to develop it in their 40s due to years of exposure to cement.

Cleaners, caterers, bakers and those in light engineering industries exposed to coolant oils are also particularly vulnerable to irritant contact dermatitis. Irritants remove from the skin the protective fatty sebaceous matter or sebum designed not only to keep the skin waterproof but to act as a barrier to other damaging substances. As Dr Robert Youngson says in Coping with Eczema: "Detergents and mild alkalis are as capable of emulsifying human sebum as they are of emulsifying fatty material hardened on to a dinner plate."

Irritant contact dermatitis can be completely healed if it is caught in time. But each time there's a further outbreak it recovers more slowly and can become more extensive.

Allergic contact dermatitis accounts for up to 30 per cent of all incidences of occupational dermatitis. If a worker becomes sensitised to an allergen at work that's likely to be readily found in other work environments, it can lead to the loss of that worker's livelihood. This frequently leads to litigation. So employers and workers alike should be aware of the allergenic potential of anything in the workplace.

Possible sources of allergic contact dermatitis include: cement, dyes, timber preservatives, pesticides, paints, fungicides, nickel, cobalt, lacquers, fly paper, soaps, cosmetics, rubber, antirust agents, perfumes, the peel of citrus fruits, epoxy resins (widely used as adhesives) and formaldehyde (used in dialysis units, coolant oils, cosmetics, clothing and deodorants). Prevention is better than cure or litigation.

If the irritant or sensitiser is not absolutely essential remove it and substitute if for something less hazardous.

If it can not be avoided or substituted use a lower concentration and spend less time in contact with it.

Pre-employment screening can help establish if subsequent dermatitis is work-related.

Suitable protective gloves should be provided (some gloves can not prevent penetration by irritants or sensitisers). Gloves should fit properly and fully protect the lower forearm. Ideally, they would have a cotton insert to reduce sweating. Workers should be trained to remove gloves without contaminating their skin and to discard damaged gloves immediately.

Skin irritations should be reported without delay to the health and safety officer.

Washing facilities must be adequate so that workers can readily wash off hazardous substances. Warm water, soap, drying facilities and emollient hand cream (which replaces the skin's oily layer) should be provided.

A master class on allergies in the workplace will be held at the Blackrock Clinic on Tuesday, February 24th at 8 p.m. It will explore work-related skin allergies and how to investigate allergy in the workplace. For reservations telephone: 01 283 2222.