Phthalates are esters of phthalic acid and are most commonly found in plastics, and primarily, in PVC as plasticisers to increase their flexibility, transparency, durability and longevity.
PVC containing the softener phthalate DEHP was first manufactured in 1931.
Due to health concerns, a number of phthalates have been proscribed for use in children's toys in the EU through listing in REACH. (see below)
In view of the phthalates listed by REACH and others, use of those phthalates, such as in PVC flooring, is being phased-out - to be replaced with alternative phthalates – the so-called non-CMR (carcinogenic, mutagenic or toxic to reproduction) classified pthalates.
Phthalates in the environment
Phthalates are used in a wide range of common products, and are easily released into the environment. Because they are not chemically bound to products, leaching, migration, and evaporation during use can occur, resulting in human exposure.
Phthalates and human health
'…people are exposed to phthalates, and most Americans tested by the Centers for Disease Control and Prevention have metabolites of multiple phthalates in their urine. Phthalate exposure may be through direct use or by indirect means through leaching and general environmental contamination. Diet is believed to be the main source DEHP and other phthalates in the general population. Fatty foods such as milk, butter, and meats are a major source.' 1
Phthalates are suspected of disrupting hormones and may be related to several chronic diseases in children, like asthma and allergies, as shown in earlier studies. Flooring materials using softened PVC contain phthalates and have previously been shown to be a significant source of phthalates in indoor dust.
A study in Sweden 2 was conducted to examine whether flooring materials using PVC and other household-related factors, together with other individual factors, could be tied to the uptake of phthalates by infants:
'The levels of certain phthalates (MBzP, a BBzP metabolite) proved to be higher in the urine of babies that had PVC materials on their bedroom floor. The levels of another phthalate metabolite related to DEHP were lower in two-month-old children if they were exclusively breastfed, with no supplements.'
'These data thus show that the uptake of phthalates in infants can be related to flooring materials using softened PVC in the home.'
'"With this study as a basis, we can establish that there are other sources that should be taken into consideration in regard to the uptake of banned chemicals and that we do not only ingest them in our food," says Carl-Gustaf Bornehag, professor of public health at Karlstad University and leader of the study. The findings also show that phthalates can be taken up in different ways, both through food and probably through breathing and through the skin.'
A report published in October 2014 claims that boys exposed in the womb to di-isononyl phthalate (DiNP) cause changes in the development of the human male reproductive tract.
Less is known about the reproductive risks of DiNP, a chemical which scientists say may be replacing DEHP in many products such as vinyl toys, flooring and packaging. In mice, high levels block testosterone and alter testicular development.
“Our data suggest that this substitute phthalate may not be safer than the chemical it is replacing,” wrote the researchers, led again by Carl-Gustaf Bornehag (see above), in the journal Environmental Health Perspectives.
Levels of DiNP in U.S. adults and children have more than doubled in the past decade.
The following phthalates are listed under REACH. They are prohibited from use in children's toys (as well as in adults' 'toys').
• Di-2-ethylhexyl phthalate(DEHP)
• Dibutyl phthalate (DBP)
• Benzylbutyl phthalate(BBP)
• Diisononyl phthalate (DINP)
• Di-n-octyl phthalate (DNOP)
• Diisodecyl phthalate (DIDP)
A number of other phthalates have been identified as Substances of Very High Concern (SVHC) and placed on the REACH Candidate List.
The following phthalates are listed by the State of California under Proposition 65 as possibly causing harm:
• Di(2-ethylhexyl) phthalate (DEHP)
• Butyl benzyl phthalate (BBP)
• Di-n-butyl phthalate (DBP)
• Di-isodecyl phthalate (DIDP)
• Di-n-hexyl phthalate (DnHP) (Not AB 1108 or CPSIA listed)
The future of plasticisers according to industry
'The EU demand for plasticisers has been steadily shifting away from CMR (carcinogenic, mutagenic or toxic to reproduction) classified phthalates towards non-CMR classified phthalates and other non-CMR classified plasticisers which today represent around 90% of all plasticisers being produced in Europe. A similar move away from CMR classified phthalates has occurred in North America, but in the rest of the world (China, India, Latin America) CMR classified phthalates including DEHP and DBP continue to be produced and used to a high degree.' (Plasticisers and flexible PVC information centre)
2 Carlstedt, F., Jönsson, B.A., Bornehag, C.G. PVC flooring is related to human uptake of phthalates in infants. Indoor Air, (accepted May 7, 2012)