Contact dermatitis is an inflammation that occurs when a substance comes into contact with skin. The skin is irritated.  This may be in the form of either an allergy or more commonly an irritant reaction. 

Areas of irritated skin may be red, swollen, tender, hot, painful or itchy. If the reaction is severe, the skin may blister or weep and can become crusty. There may be some scaling as the skin heals. 

Skin affected for several weeks by dermatitis tends to thicken and change to a deeper colour. 

Sometimes there may be a reaction only when direct sunlight and an irritating substance are on the skin at the same time. This kind of contact dermatitis looks a lot like sunburn. 

Scratching or rubbing itchy skin can make dermatitis symptoms worse. 

In women, contact dermatitis occurs most frequently in hairdressing, food handling, nursing, and cleaning, whereas it most commonly affects men who are plant operators, construction workers, food handlers, labourers, and mechanics. 

Many of the chemicals used in industry will cause a sudden and very strong irritant or corrosive reaction when they come into contact with bare skin. Safe work systems should be developed for such substances as: 

• acids; 
• alkalis; 
• oils; 
• solvents; and 
• petroleum products.

Wet work, sweating, heat, dust, friction and prolonged glove use may also cause or contribute to irritant contact dermatitis. 
Some products that may cause allergic contact dermatitis are: 

• cement (due to traces of hexavalent chromium); 
• powdered latex gloves;
• synthetic rubber (may have traces of thiurams, dithiocarbamates, diphenylguanidine or thioureas); 
• plastics; 
• fibreglass; 
• epoxy resins (used in flooring, marine paint and adhesives); 
• acrylates used in dentistry or in artificial nails;
•  isocyanates (found in 2-pack vehicle paints and in foam manufacturing);
• hair dyes (even if labelled “Natural” or “Organic” they may contain paraphenylenediamine(PPD) or toluene-2,5-diamine sulphate which are allergenic); 
• hair bleach (eg ammonium persulphate);
• tattoos (eg “henna” tattoos which may contain PPD)
• glue; 
• hand wash (may contain traces of coconut diethanolamide, lanolin, fragrance, cocamidopropylbetaine, chlorhexidine);
• preservatives (eg methylchloroisothiazolinone, methylisothiazolinone, chloroacetamide, formalin, iodopropynyl butylcarbamate); 
• shellfish; and 
• metal objects with nickel or chromium content. 

Natural plant and animal products may cause a skin reaction in some people. Sawdust from some varieties of wood and natural oils used in perfume are some of the plant products that may cause a reaction. 

Sometimes the skin may be affected by chemicals used to process natural products - such as the dyes in leather, fur, wool and cotton, and preservatives in cosmetics, creams and ointments. 

Different people will react differently to each substance, and some workers may not be affected by them at all.

Some irritating substances will have an immediate and obvious effect on the skin. Other substances could be used regularly for a long time before the skin begins to react. After the first reaction occurs, dermatitis will develop fairly quickly each time there is contact with that substance. 

As well as causing pain or discomfort, dermatitis in some cases can result in long periods away from work. At times the same work cannot be resumed because the person has become sensitised to the substance. 

Persons conducting a business or undertaking (PCBUs) are required by work health and safety legislation to eliminate risks to health and safety so far as reasonably practicable, or otherwise to reduce risks so far as reasonably practicable.  Specific actions to reduce risk include: 

• Provide safety data sheets for hazardous chemicals; 
• Substitute a safer alternative substance or product. For example, replace powdered latex gloves with unpowdered latex gloves or disposable nitrile gloves; 
• Include information about contact dermatitis in your safety training programme; 
• Keep the work area clean; 
• Provide personal protective equipment (PPE) and barrier creams where appropriate; and
• Take additional precautions for workers with known allergies. 

Workers are required by law to protect themselves by following the PCBU’s safe work practices and using the PPE provided. 

Wash hands with a mild soap and water, and then dry them thoroughly after work. Use a cleanser made from vegetable oil to remove grease or other substances that will not come off with soap and water. Some barrier creams applied before work may make it easier to remove substances that tend to stick to the skin or provide some protection from wet work. 

• Do not use solvents like kerosene or turpentine for cleaning hands!
• Do not use barrier cream on damaged skin. 
• Treat minor cuts and abrasions promptly. 

If you suspect that you have contact dermatitis, see your doctor. Early treatment is important for best results. Speak with your health and safety representative and PCBU about how to overcome the problem and make the workplace safe.