Using pipetting aids eliminates this risk. Ingestion also occurs when toxic materials are transferred from contaminated hands to food or cigarettes. Over time, small doses of systemic poisons can lead to systemic diseases such as central nervous system disorders, kidney and liver dysfunction, and cancer. Cuts, abrasions and skin punctures provide an even easier route for penetration. Like ingestion, chemical absorption through the skin can lead to systemic diseases.
Some chemicals react on the skin surface, causing dermatitis.
Symptoms range from simple reddening, drying and itching associated with some detergents to blistering or severe burns from strong corrosives. Protective equipment such as gloves, lab coats, aprons, safety glasses, and face shields are the best ways to avoid skin contact with chemicals. Small amounts of contamination that may not affect the rough skin of the hands can cause irritation if transferred to more sensitive areas such as lips, eyes or genital areas. Therefore, wash hands before applying cosmetics or using the bathroom. Inhalation is the third route of entry.