- Phthalates have been used as plasticisers
in many plastics since the 1930's, with a quarter of the total
plasticiser ever produced being diethylhexylphthalate (Kirk-Othmer's
Encyclopaedia). In the UK they are no longer used in the manufacture
of cling film or most other food contact plastics (MAFF, 1996a).
- The ink used to print on plastic, board
and foil-packed products frequently contains phthalates, as do
some of the adhesives used in packaging (MAFF, 1996a).
- They are found in products such as baby
milk formula, cheese, margarine and crisps ('chips' in the USA).
- Also found in vinyl flooring, emulsion
paint and PVC baby toys.
- Phthalates used include diethylhexylphthalate
(DEHP), monoethylhexylphthalate (MEHP), dimethylphthalate(DMP),
butylbenzylphthalate (BBP), dibutylphthalate (DBP) and dioctylphthalate(DOP).
Phthalates are fat soluble, so tend to
concentrate in materials such as butter, margarine and cheese.
In addition, they are likely to accumulate in body fat.
Several phthalates, particularly DEHP,
are testicular toxicants. Part of this toxicity is believed to
involve depletion of testicular Zinc, and may include the death
and disintegration of the testicular germ cells (Amdur et al.,
1991; Peters et al., 1997).
Occupational exposure to high levels of
phthalates has been reported to lead to miscarriages and other
complications of pregnancy (IEH, 1995)
BBP is oestrogenic in the E-SCREEN assay,
which uses a human breast cancer cell culture, MCF-7 (Soto et
al., 1995). Both BBP and DBP were oestrogenic to a different
breast cancer cell line, bound rainbow trout oestrogen receptor
and initiated the transcriptional activity of the oestrogen receptor
(Jobling et al., 1995). Both BBP and DBP were agonists of the
oestrogen receptor - their action is cumulative, adding to any
oestrogen already present.
BBP can also act as an antiandrogen, blocking
the action of dihydrotestosterone in a yeast screen containing
a human androgen receptor (Sohoni and Sumpter, 1998). In this
screen BBP was approximately as potent as flutamide, a well known
Research at the Chemical Industry Institute
of Toxicology confirmed that DBP does damage the reproductive
system of male rats at low exposures, however this research suggested
that DBP was disrupting the androgen system rather than imitating
oestrogen (Foster, 1997). Further research has established that
DBP cannot bind the androgen receptor, but does disrupt androgen-regulated
male sexual differentiation (Mylchreest et al., 1999). This research,
funded by the chemical industry, demonstrates that DBP is an
endocrine disrupter, though maybe not an oestrogen.
Both DBP and DEHP caused irregularities
in male sexual differentiation when given to pregnant rats (Gray
et al., 1999). DEHP caused testicular and epididymal abnormalities,
whilst in a multigenerational study DBP caused malfunctions including
retained nipples and hypospadias.
Many teethers and soft toys contain phthalate
plasticisers, and research has shown that these plasticisers
can leach out of the toys into the mouths of the children chewing
them. There is now a huge international debate on the safety
of these toys and their alternatives. Much of the work has been
carried out by Greenpeace; their initial campaign information
The EU Scientific Committee on Toxicity, Ecotoxicity and the
Environment has produced several reports on the subject, which
are available on
their web site.
From household goods
The phthalate diethylhexylphthalate (DEHP)
is used in many PVC building materials, for example PVC flooring.
Researchers have found that DEHP, and other phthalates, are present
on household dust, so will be inhaled by both children and adults.
Infants breath twice as much air as adults (per kilo body weight),
and spend most of their time indoors, so will be getting a particularly
large dose of phthalates from dust (Oie et al., 1997). Disturbingly,
animal experiments indicate that MEHP, a metabolite of DEHP can
irritate lungs (Doelman et al., 1990). Other research suggests
that there is an association between PVC flooring and the development
of bronchial obstruction in children (Jaakkola et al., 1999).
This research suggests that the increasing incidence of asthma
could be partially due to the increasing household use of plastics
containing phthalates over the last few decades.
Many of the bags and tubes used in hospitals
are made of PVC and leach phthalate plasticisers. There's a lot
of information on this subject at the Health
Care Without Harm site.
A major human exposure to phthalates is
believed to be from foods which have absorbed the chemical from
their packaging, or from manufacturing processes. The UK Ministry
of Agriculture, Fisheries and Food have done a range of studies
In a study of formula baby milk published
in 1996 all 15 brands of baby milk formula tested by the UK Ministry
of Agriculture, Fisheries and Food contained phthalates. The
highest total phthalate concentration found was 10.2 mg/kg, and
the highest concentration of BBP found was 0.25 mg/kg. Using
the manufactures' feeding guides it was estimated that a new
born infant would receive , on average, 0.13 mg/kg body weight/day
of total phthalate, falling to 0.10 mg/kg/day at 6 months (MAFF,
However, a more recent MAFF survey, published
in December 1998, found levels ten times lower. It is not clear
what the reason for this is - it could include improved production
techniques, or possibly changes in analytical technique (ENDS,
1998; the MAFF report is on the web here).
MAFF studies have found that phthalate
levels in foods like crisps, chocolate bars and cheeses are in
the tens of mg per kg range. The highest level found in dairy
produce was 114 mg/kg in soft cheese (ENDS, 1995).
Phthalates, particularly DBP and DEHP,
were also found in products packaged in paper and board, such
as cakes, fats and confectionery. The highest concentrations
of DBP found were in gravy granules (62 mg/kg), vegetable burger
mix (10 mg/kg), vegetable fat (8.4 mg/kg), chocolate coated cakes
(5.8 mg/kg) and sausages (4.4 mg/kg). The highest concentrations
of DEHP were 25 mg/kg in cookies and 11 mg/kg in vegetable fat
A survey of phthalate levels in fatty food
samples taken as part of a 'Total Diet Survey' in 1993 found
phthalates to be present in every sample, including in meat,
fish, eggs, milk and milk products. These analyses led to a prediction
that the daily intake of phthalates by an adult averaged 0.8
mg/person/day (0.013 mg/kg body weight/day), up to 1.6 mg/person/day
(0.027 mg/kg body weight/day) for someone with a diet high in
phthalate-containing products (MAFF, 1996a).
Due to their persistence in the environment,
phthalates are also commonly found in groundwater, rivers and
drinking water (Jobling et al., 1995). Researchers in Holland
have found up to 3.5 micro-g/l of DEHP in drinking water (ENDS,
This page was last
updated in October 1999
to the hormone disrupting chemicals home page
Amdur et al. 1991. Casarett and Doull's
Toxicology: The Basic Science of Poisons, 4th Ed., p499.
Doelman, C. J. A., Borm, P. J. A. and Bast,
A. 1990. Plasticisers and bronchial hyperreactivity. The Lancet
ENDS 1995. Packaging industry failing to
act over phthalates in food. ENDS Report 245: 7-8.
ENDS 1996. Denmark takes lead in curbs on
oestrogenic chemicals. ENDS Report 252: 35-36.
ENDS 1998. Food industry blames MAFF for
phthalate scare. ENDS Report 287: 12-13.
ENDS, 1999. Industry glimpses new challenges
as endocrine science advances. ENDS Report 290, p26-30.
Foster, P. M. D. 1997. Assessing the effects
of chemicals on male reproduction: Lessons learned from di-n-butyl
phthalate. Chemical Industry Institute of Toxicology.
Gray, L. E., Wolf, C., Lambright, C., Mann,
P., Price, M., Cooper, R. L. and Ostby, J. 1999. Administration
of potentially antiandrogenic pesticides (procymidone, linuron,
iprodione, chlozolinate, p, p'-DDE, and ketonazole) and
toxic substances (dibutyl- and diethylhexyl phthalate, PCB 169,
and ethane dimethane sulphonate) during sexual differentiation
produces diverse profiles of reproductive malformations in the
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to human health and wildlife. Institute for Environment and Health,
Jaakkola, J. J. K., Øie, L., Nefstad,
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surface materials in the home and the development of bronchial
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M. G. and Sumpter, J. P. 1995. A variety of environmentally persistent
chemicals, including some phthalate plasticizers, are weakly estrogenic.
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MAFF 1995. Food Surveillance information
sheet number 60: Phthalates in paper and board packaging. UK Ministry
of Agriculture, Fisheries and Food.
MAFF 1996a. Food surveillance information
sheet number 82: Phthalates in food. UK Ministry of Agriculture,
Fisheries and Food.
MAFF 1996b. Food surveillance information
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Agriculture, Fisheries and Food.
Mylchreest, E., Sar, M., Cattley, R. C.
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Øie, L., Hersoug, L.-G. and Madsen,
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Peters, J. M., Taubeneck, M. W., Keen, C.
L. and Gonzalez, F. J. 1997. Di(2-ethylhexyl)phthalate induces
a functional zinc deficiency during pregnancy and teratogenesis
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