Careful selection and use is essential. Care should be taken to avoid accidental inhalation, ingestion or skin absorption. The following free textile information sheets are available from the Health and Safety Executive, or from other industry organisations:
- Dyes and chemicals in textile finishing : an introduction (Textile Information Sheet No 1)
- Non-dyestuff chemicals : safe handling in textile finishing (Textile Information Sheet No 2)
- Dyestuffs: Safe handling in textile finishing (Textile Information Sheet No 3)
- Hazards from dyes and chemicals in textile finishing: a brief guide for employees (Textile Information Sheet No 4)
- Reactive Dyes ; Safe handling in textile finishing (Textile Information Sheet No 5)
- Dust control in dyestuff handling (Textile Information Sheet No 6)
- Selection and safe use of spotting solvents in textile and clothing industries (Textile Information Sheet No 7)
Dye powders are very fine, and therefore dangerous if inhaled. They should be mixed when wholly immersed in water or, if this is not possible, a dust mask or respirator should be worn. Heavy-duty rubber gloves should be worn to avoid skin contamination. Cooking utensils should not be used, as they may retain potentially hazardous amounts of chemicals. Personal protective clothing should be worn and there should be no eating, drinking or smoking in a dyeing area. Only soap and water should be used to remove splashes from the skin, as chemical substances such as bleach or potassium manganate (VII) might break down the dyes into hazardous substances.
Direct benzidine-type dyes are a component of all-purpose dyes. These may be toxic and care should be exercised.
These are used for silk and wool, and are probably the least hazardous.
These dyes, used for wool, silk and some synthetics, may cause allergic reactions.
These are also known as fibre-reactive or cold water dyes. Reactive dyes are extremely reactive chemical compounds and are capable of reacting with body tissue. The respiratory tract is particularly sensitive to reactive dyes and allergic responses may occur. Symptoms may seem like hay fever or asthma, accompanied by swollen eyes.
Synthetic Mordant Dyes
These may be used in dyeing wool, and the most hazardous mordant salt is potassium dichromate. Other metal salts such as chromium cobalt, copper and so on may be both toxic and corrosive, and it is recommended that alum (potassium aluminium sulphate) salts of tin or iron be used instead.
The constituent materials of these dyes, 'fast bases' (fast salts) and 'napthol', are highly reactive chemical compounds capable of causing dermatitis and other skin disorders.
CLEAPSS guidance - MRAT - 097 - Dyes and Mordants
CLEAPSS guidance - MRAT - 171 - Projects, Testing, Experimental & Novel Activities Materials