I for Intolerance to wood species  Part 1

This time we examine the effects certain types of wood can have on the human body.

Many timbers are used regularly without causing any health problems for the woodworker, however, the risk of any adverse health effects arising may depend upon the following: -  

Health risks can arise from the wood itself, the wood dust or the sap, latex or lichens associated with the wood. Splinter wounds from some woods such as greenheart often turn septic and are slow to heal.

Hardwoods are often used for veneers and also for composite materials such as plywood so we need to be aware that these materials can also cause health risks.

Parts of the body which may exhibit ill health associated with wood are primarily the skin, respiratory system, eyes or the whole body.

Skin can be irritated by contact with the wood, wood dust, bark, lichens growing on the bark or the sap of the wood. Irritation by some species can lead to nettle rash or irritant dermatitis. Direct contact or cross-contamination by the hands can result in the effects appearing on forearms, backs of hands, the face particularly around the eyes, neck, scalp and genitals. On average symptoms take 15 days to develop. They usually only persist as long as the affected skin site remains in contact with the source of irritation.

Sensitisation dermatitis

is caused by exposure of skin to fine dust of certain wood species. Also known as allergic contact dermatitis it gives similar effects to skin irritants, however, once sensitised the body sets up an allergic reaction and the skin may react severely if subsequently exposed to even very small amounts of wood dust. Rashes may appear on skin well away from the original point of contact. Cross-sensitisation may develop where other species or even other materials produce a similar reaction.