This site includes a lot of information
on alkylphenols, including the full text of a report I wrote
on their oestrogenic affects in 1994, which was published by
Friends of the Earth in 1995. This page is the introduction,
whilst the alkylphenols in depth page
covers some issues in more depth.
Alkylphenols such as nonylphenol and octylphenol
are mainly used to make alkylphenol ethoxylate (APE) surfactants
(detergents), though alkylphenols themselves can be used as plasticisers
in plastics, and the derivatives alkylphenol phosphites can be
used as UV stabilisers in plastics.
In Europe alkylphenol ethoxylates are
- Industrial detergents, such as those used
for wool washing and metal finishing.
- Some industrial processes, such as emulsion
- The spermicidal lubricant nonoxynol-9.
- Various laboratory detergents, including
- In some pesticide formulations.
alkylphenol ethoxylates are also used in many domestic products;
for example in the USA they are in many liquid clothes detergents.
In Europe these products contain the slightly more expensive,
but much safer, alcohol ethoxylates.
Hormone disrupting effects
Alkylphenols were first found to be oestrogenic
(oestrogen-mimicking) in the 1930s (Dodds and Lawson, 1938),
and more evidence was published in 1978 (Mueller and Kim, 1978).
However, it was only in 1991 that publication of the effects
of nonylphenol on cultured human breast cells led to health concerns
(Soto et al., 1991). This and more recent research has shown
that the growth of these cells is increased by alkylphenols at
concentrations 1000 to 10000 times higher than the oestradiol
levels required to produce the same growth. Oestrogenic effects
have also been shown on rainbow trout hepatocytes, chicken embryo
fibroblasts and a mouse oestrogen receptor (Jobling and Sumpter,
1993; White et al., 1994). Oestrogenic effects are present at
tissue concentrations of 0.1 µM for octylphenol and 1 µM
for nonylphenol (Soto et al., 1995). A recombinant yeast screen
using the human oestrogen receptor has shown similar results
(Routledge and Sumpter, 1996).
Recent research is showing oestrogenic
effects of nonylphenol at ever lower concentrations. Levels of
0.05 micro-g per litre were enough to increase the number of
eggs produced by minnows, as well as increasing vitellogenin
levels (ENDS, 1999b). This research also suggested that nonylphenol
was leading to an increase in natural oestrogen levels.
Fate in the Environment
APEs do not break down effectively in sewage
treatment plants or in the environment. They tend to loose some
of their ethoxylate groups quite easily, which prevents them
acting as detergents - this is called 'primary biodegradability'.
This leaves alkylphenols, alkylphenols with one or two ethoxylate
groups and alkylphenoxy carboxylic acids (APEC) , which persist
for longer. Alkylphenols accumulate where there is inadequate
oxygen, e.g. in sediments, whilst APEC persist in rivers and
effluents, for example analysis of sewage effluents found that
these compounds accounted for 63% of total alkylphenolic metabolites
(Di Corcia et al., 1998).
In spite of how important APEC are in the
environment, they are often not tested for in the environment,
so only a partial measurement of contamination is made. Any water
analyses for pollution must measure all APE metabolites, including
the alkylphenoxy carboxylic acids - if they don't then they're
Alkylphenolic compounds are concentrated
by organisms such as fish and birds, leading to contamination
in their internal organs between ten and several thousand times
greater than in the surrounding environment.
Another source of nonylphenol ethoxylate
contamination to the environment in the UK is the ICI plant at
Much of the key research on the fate and
levels of alkylphenolic compounds in the environment has been
done be Dr Marijan Ahel who has been quoted as saying "In
1990, industry said a phase-out was not possible. Now after ten
years they admit it is possible and we have not sacrificed anything
from our daily lives". He also said that companies had spent
"several million dollars" repeating his work: "the
science is the same - it is only the emphasis that is different"
"What happens in sensitive environments they don't show.
Something that stays in the river just several days is great
enough to have an effect." (ENDS, 1999b).
Human exposure routes
Alkylphenols as air pollution
Surprising new US research has revealed
that nonylphenol is present as an air pollutant in the New York
and New Jersey urban atmosphere, apparently due to vapourisation
from the Hudson River (Dachs et al., 1999). The authors state:
"the high concentrations found
in the coastal atmosphere of the New York-New Jersey Bight (2.2
- 70 ng/m3) suggests that the NPs occurrence in the atmosphere
may be an important human and ecosystem health issue in urban,
industrial, and coastal-impacted areas receiving treated sewage
Alkylphenols in water pipe treatments
Research by the UK Government's Drinking
Water Inspectorate has shown that various products for drinking
water pipes leach alkylphenols and phthalates into the drinking
water. One epoxy resin leached 1,400 micro-g of dibutyl phthalate
per square metre into water in the first hour after curing; a
cement coating leached 12,000 micro-g per square metre of nonylphenol
ethoxylate immediately after curing, with continued high leaching
for 3 days (ENDS, 1999c).
Other exposure routes
Human exposure to these chemicals may also
be occurring by the following routes:
- Absorption through skin from shampoos,
cosmetics, spermicidal lubricants and domestic and industrial
- Contaminated drinking water, extracted
from polluted rivers.
- Inhalation and ingestion from pesticide
- Contamination of food from fields spread
with sewage sludge containing alkylphenols.
Contamination of the body
Nonylphenol and bisphenol a have both been
detected in human umbilical cords at up to 2 parts per trillion
wet weight for nonylphenol and 1.6.ppt for bisphenol a (ENDS,
Many individual EU member states and other
European countries have already brought in controls on alkylphenols,
for example Switzerland has already banned the use of all alkylphenol
ethoxylates, and the UK has had a voluntary agreement
against the use of alkylphenols in domestic cleaning products
However, trans-national controls also exist,
through the OSPAR agreement on marine pollution of the
North East Atlantic, which includes an agreement to phase out
the use of nonylphenol ethoxylates as cleaning agents by 2000
Alkylphenols are also being assessed by
the complex European Union Existing Substances process.
A draft risk management document has now been produced by the
UK, which proposes a range of bans on alkylphenol use, including
industrial and institutional cleaning, textiles, leather, pulp
and paper, metal working, cosmetics and agricultural sectors
(ENDS, 1999a). It also proposes limits on discharges from NPE
production, emulsion polymerisation, phenol/formaldehyde production
and plastic stabiliser industries.
This regulatory pressure is forcing many
companies to phase out APEs, for example ten major manufacturers
of polyacrylamide emulsions have agreed to phase out APE use
in Europe by the end of 2001 (ENDS, 1998).
It is now becoming likely that the US will
take some sort of regulatory action against alkylphenols, though
there is heavy chemical industry lobbying against controls, e.g.
The 'Alkylphenol Ethoxylates Research Council' (ENDS, 1999b).
The Washington Toxics Coalition has produced
a report on alkylphenol use in the USA, "Troubling Bubbles:
The Case for Replacing Alkylphenol Ethoxylate (APE) Surfactants".
More information is available on their web