Ear plugs may be custom fined or preformed rubber, plastic, or foam inserts. Preformed inserts are cheaper, but ear plugs properly inserted into the ear and custom-fitted by trained personnel are more effective because the ear canal shape may vary. If you are continually exposed to loud noises, you should have periodic hearing tests. This test, called an audiogram, will reveal signs of hearing loss. If a hearing loss is noted, take steps to reduce exposure, thereby eliminating further damage to your ears.
Irritants act directly on the skin at the place of contact.
Allergic sensitizers, however, cause changes in the immune system so that subsequent contact produces a reaction. Phototoxic or photoallergic reactions occur when light, in combination with certain substances, causes skin disease. Other types of agricultural dermatitis include heat rash, origin infections, and insect and plant irritants. A number of factors predispose an individual to dermatitis, such as age, sex, race, temperature and humidity, previous skin disorders, skin damage, and personal hygiene. Work-related skin diseases are often easy to detect, but difficult to diagnose.