Phthalates

Latest Edit: Iva 2012-08-04 (EDT)

Phthalates are one of many environmental chemicals. They are added to plastics to impart resilience and flexibility. Smaller phthalates are used to prolong the length of time that a scented product maintains its fragrance. Phthalates are classified as DEHP, DINP, DIDP, DBP, DnOP, DnHP.

Sources

• Personal care products such as soaps, shampoo, hair spray, nail polish, and toothbrushes, baby-care products, diethyl phthalate reported in 70% of cosmetic products tested.

• Most widely used plasticizers for the manufacture of polyvinyl chloride (PVC) plastics utilized in vinyl flooring and tile, wall covering, pool liners, tool handles, insulation of wires and cables, garden hoses, construction materials, weather-stripping, canvas tarps, upholstery, some food wrappers and containers, medical equipment containing flexible plastics such as blood bags and tubing, haemodialysis, children's toys, dishwasher baskets, notebook covers, flea collars, faux leather, shoe soles, traffic cones, latex adhesives, dyes, some pharmaceutical and pesticide formulations.

• Detergents, lubricating oils, automobile parts, automobile undercoating, carpet backing, solvents

• Occupational Exposure: such as plasticizer and processing plants

• Quinolinate: Phthalate esters perturb tryptophan metabolism resulting in the accumulation of quinolinic acid, an endogenous excitotoxin implicated in inflammatory neurological disorders.

Impact on Health

• Endocrine-Disrupting Chemical (EDC)

• Young infants may be more vulnerable to toxic effects. May alter development of male reproductive system

• Developmental and morphological abnormalities including deficits in behaviour and cognition.

• Decreased sperm production in adult males exposed to environmental levels.

• Has been found to be associated with increased waist circumference and insulin resistance in adults.

Metabolism

• Phthalates are hyrdrolyzed in the gut by pancreatic lipase yielding ester derivatives, which are rapidly absorbed. These phthalate esters are metabolized in the liver by cytochrome P-450 dependent multifunction oxidase enzymes, into glucuronide conjugates and excreted in the urine.

• Monoethylphthalate, MEP, in urine reflects exposure to diethylphthalate (DEP). About 70% is excreted in urine as its free mono-ester. DEHP represents another widely used plasticizer in the manufacture of PVC. Urinary levels of free phthalic acid, a breakdown product of phthalates, indicates exposure to DEHP and phthalates in general.

• Phthalates and their metabolites are found to accumulate in lipid depots. Chronic exposure may result in bioaccumulation.