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Phthalates Introduction

Phthalates are “plasticizers” used to produce diverse products, including food and beverage packaging materials, medical devices and products, flexible tubing, electrical conduits, building products, lubricants, perfumes, hairsprays, cosmetics, construction materials, wood-finishers, and adhesives. Phthalates are additives that give plastics like polyvinyl chloride (PVC) properties such as flexibility and stress resistance. Six phthalates are in common use (see Table 5). However, di(2-ethylhexyl) phthalate, commonly known as DEHP, has received the most regulatory and scientific attention due to the strength of evidence demonstrating its testosterone-blocking potential in males.

Nearly 240 million pounds of DEHP were produced in 2002, a figure that represents a quarter of all plasticizers produced. Most DEHP is added to PVC plastics produced from vinyl chloride. It is often mixed with plasticizers (softeners), heat stabilizers such as lead, cadmium, zinc, and tin, as well as lubricants, and other additives that affect both mechanical and physical properties. Some vinyl contains 40% DEHP. DEHP is the focus of this section of our report, because it has the greatest potential for endocrine disruption among all phthalates, and has received the greatest attention of all the phthalates due to the strength of evidence of its potential to disrupt health in laboratory studies.

Nearly 15 billion pounds of PVC plastics are produced each year. The chemical complexity and diversity of PVC plastics make them difficult and expensive to sort and recover. The effect is that a very small proportion (0.1–0.5%) are recovered through recycling efforts.

Recovery failure, in turn, means that the majority is released to the environment in landfills or via incineration. If placed in landfills, the chemical often leaches into groundwater. If burned, a variety of highly toxic chemicals is produced and often released to the atmosphere. These include polychlorinated dibenzodioxins (PCDD), and polychlorinated dibenzofurans (PCDF), both well recognized for their hazard to human health. These chemicals are often released from incinerators, and also from accidental fires that burn materials containing PVC plastics, such as vinyl flooring, paints, wall coverings, electrical wiring, and vinyl siding.

The enormous volume of PVC in consumer and industrial products, its persistence, and its routine disposal to the environment help to explain why human exposure to DEHP is nearly ubiquitous. DEHP has been found in human blood, seminal fluid, amniotic fluid, breast milk, and saliva. Our focus on DEHP is explained by the strength of evidence of human exposure and the relative clarity of animal evidence of health hazard in comparison with other phthalates, briefly summarized below.

DEHP

DEHP causes reproductive and developmental damage in animal studies. These studies are plausibly relevant to humans, especially male infants, children, and pregnant and lactating women.

BBP  

Studies report reproductive toxicity in adult rats and developmental toxicity in rats and mice are assumed relevant to humans.

DBP  

Studies report developmental toxicity among exposed rats and mice.

DINP  

Child exposure via children’s products is common and children may be exposed to 10-to 100-fold higher levels than adults by mouthing toys and other articles containing DINP. Quality of toxicological evidence is weaker than for DEHP. 

DNOP

Data are limited or inadequate.

DIDP

Children may have higher levels of exposure than adults if they mouth toys and other objects that contain DIDP.
   

 

 

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