Plasticisers - essential to our everyday lives

Without plasticisers, unique PVC products such as electrical cables, synthetic leather and many life-saving medical devices, would not exist today.

A plasticiser is a substance which when added to a material, usually a plastic, makes it flexible, resilient and easier to handle. Early examples of plasticisers include water to soften clay and oils to plasticise pitch for waterproofing ancient boats. Today, modern plasticisers are manmade organic chemicals; esters, such as adipates and phthalates.

Importantly, they are not just additives (like pigments or fillers), they are major components that determine the physical properties of polymer products.

Phthalates

The most commonly used plasticisers are phthalates. They are colourless, odourless liquids produced by a simple chemical reaction, whereby molecules of water are eliminated from commercially produced petrochemical products.

Many different plasticisers are produced but less than 100 are in commercial use. In Western Europe approximately one million tonnes of phthalates are used each year, predominantly to plasticise PVC (polyvinyl chloride) to make flexible PVC products. The most common phthalates are di-2-ethyl hexyl phthalate (DEHP, also sometimes called DOP), diisodecyl phthalate (DIDP) and diisononyl phthalate (DINP).

We use many PVC products  everyday but tend to take them for granted. They include everything from lifesaving medical devices such as medical tubing and blood bags, to footwear, electrical cables; packaging, stationery, toys and the roofing for large structures like the one above. In addition, phthalates are used in other non-PVC applications such as paints, rubber products and some adhesives.

Phthalates are found in the environment but the levels are so low (and falling) as to pose no risk to the environment or to human health. This is true for all phthalates and has been clearly acknowledged in the independent EU risk assessments that have been carried out on all the major phthalates. Phthalates are biodegradable and do not bioaccumulate.

Aggregating exposures is only valid for substances that act via additive mechanisms. For phthalates, there is no evidence to support the additive theory. To the contrary, there is evidence to refute it. Not all phthalates act the same, and none have shown adverse effects on laboratory animals unless the dose is very large. So, arguing that phthalate exposures are additive is a good scare tactic, but not good science.