These are a diverse group of multifunctional, compounds which may occur as dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), diisobutyl phthalate (DIBP), dimethoxyethyl phthalate (DMEP), di-n-octyl phthalate (DNOP), diisononyl phthalate (DINP), benzyl butyl phthalate (BBZP), di 2-ethylhexyl phthalate (DEHP), diisodecyl phthalate (DIDP), di-n-hexyl phthalate (DNHP), and di-n-octylphthalate (DNOP).

Phthalates are included in personal care products for a number of reasons: softening the skin; as a penetration enhancer; denaturing alcohol, and as a fixating agent (to, for example, fix fragrances for them to last longer). In deciding whether or not to use phthalate-containing personal care products, it is important to be aware that one of the starting materials for the preparation of phthalates is phthalic anhydride, a highly toxic chemical with a characteristic choking odor. Inhaling phthalic anhydride irritates the mucous membranes, which can lead to copious discharge from the nostrils and sometimes bleeding.

Phthalates have wide applications in the medical, textile, construction, pharmaceutical, food, packaging, and agricultural field. They’re present in many polyvinyl chloride, plastic, and medical devices like blood bags, surgical gloves, catheters, and infusion containers. Over time, phthalate plasticizers can leach out chemicals into the products or solutions they contain.

Phthalates exposure is via skin contact, ingestion, and inhalation. The chances of skin absorption of higher molecular weight phthalates is low. However, lower molecular weight ones like DMP and DEP, which are often found in personal care products, can be rapidly absorbed.

Acute toxicity of phthalates usually occur as marked irritation of the skin, eyes, and the respiratory tract. Continuous contact causes allergic dermatitis and pulmonary sensitization which can lead to asthmatic attacks. Phthalates are endocrine disruptors; increasing levels of exposure adversely affect reproductive organ development in males. Increasing exposure levels also lead to endometriosis (abnormal tissue growth outside the uterus wall) and early puberty in girls. Several concentrations of phthalates have been found to correlate significantly with insulin resistance and abnormal obesity.

DEP, DMP, and lower molecular-weight phthalates, which are often included in personal care formulas, can pass into our urine. They can be passed onto babies during pregnancy due to the rapidity with which they can cross the placenta. After birth, babies can be exposed through breast feeding. Repeated inhalation can result in irritation of the upper respiratory tract and nasal passage mucous membrane. Prolonged inhalation may lead to central nervous system depression and paralysis.

Environmental advocates have raised concern about phthalate plasticizers. They maintain that these plasticizers can leach their hazardous contents into water bodies and then be absorbed by fish and other aquatic organisms, impacting their survival.

Phthalates are considered safe in the US. In Australia, certain phthalates (e.g. DBP, DEHP, and DIBP) have been prohibited from inclusion in personal care products. Some phthalates, e.g. DEHP, have also been banned from some children’s toys and products.