Most detergents are
formulated products containing surfactants which remove dirt,
stains, and soil from surfaces or textiles. Surfactants consist
of a hydrophobic and a hydrophilic component and have the
ability to change the surface properties of water. Surfactants
are grouped according to their ionic properties in water:
- Anionic surfactants have a negative charge;
- Non-ionic surfactants have no charge;
- Cationic surfactants have a positive charge;
- and Amphoteric surfactants have positive or negative
charge dependent on pH.
Surfactants have low oral acute toxicity. In general,
surfactants have an irritating effect on mucous membranes.
Foaming is the predominant problem. Manifestations may also
include vomiting, abdominal pain, flatulence and diarrhoea. In
rare cases, vomiting or formation of considerable amounts of
foam in the mouth involve an aspiration risk. Aspiration may
have taken place if a persistent cough and respiratory
complaints are observed. For healthy children and adults,
ingredients containing surfactants such as shower gels, bubble
baths, shampoos, all-purpose cleansers or liquid
detergents do not
pose a particular risk. But they may be life threatening or even
fatal for elderly persons because they are more prone to foam
aspiration after vomiting, which may result in severe pulmonary
manifestations and a fatal outcome (Hahn et al. 2008).
The toxicity studies performed with animals show that, in
general, surfactants are of low toxicity.
Anionic surfactants (AS) are readily absorbed from the
tract after oral administration. AS are extensively
metabolized in various species resulting in the formation of
several metabolites. The
major site of metabolism is the liver (Gloxhuber and Künstler
1992, IPCS 1996). The acute toxicity of AS in animals is
considered to be low after skin contact or oral intake.
Non-ionic surfactants are widely used in consumer products
such as laundry
detergents, cleaning and
dishwashing agents, and personal care products. By volume, the
most important non-ionic surfactants are included in the very
versatile group of alcohol
ethoxylates (AE) and alcohol alkoxylates (AA).
AE are used in many types of consumer and industrial products
such as laundry
cleaning agents, dishwashing agents, emulsifiers, and wetting
agents. AA are used as weakly foaming and foam-mitigating
surfactants in household cleaning agents, dishwashing agents and
cleaning agents designed for the food industry (Bertleff et al.
1997). In general, AE are readily absorbed through the
gastrointestinal mucosa of rats. AE are quickly eliminated from
the body through the urine, faeces, and expired air (CIRP 1983,
SFT 1991). The LD50 values after oral administration to rats
range from about 1-15 g/kg body weight indicating a low to
moderate acute toxicity.
By volume, the most important cationic surfactants in
household products are the alkyl ester ammonium salts that are
used in fabric softeners. Alkyltrimethylammonium chlorides
(ATMAC) and, to a minor extent, alkyltrimethylammonium bromides
(ATMAB) are primarily used in cosmetic products including hair
conditioners, hair dyes and colours, and other hair and personal
care preparations. Studies after oral administration showed that
only small amounts were found in the urine and in the blood
plasma, indicating poor intestinal absorption (Isomaa
The acute oral toxicity of alkyltrimethylammonium salts is
somewhat higher than the toxicity of anionic and non-ionic
surfactants. This may be due to the strongly irritating effect
which cationic surfactants exhibit on the mucous membrane of the
tract (SFT 1991). Dialkyldimethylammonium chlorides
(DADMAC) are used as antistatic agents in cosmetic products
including hair conditioners and hair colouring preparations and
as biocides in industrial and household cleaning agents. No
specific data describing the health effects of
dialkyldimethylammonium salts were obtained. However, many of
the properties described for alkyltrimethylammonium salts also
apply to dialkyldimethylammonium salts, although these are
generally less irritating than the corresponding
alkyltrimethylammonium salts (CIRP 1997).
Alkyldimethylbenzylammonium chlorides (ADMBAC) and bromides
(ADMBAB) are used in cosmetic products including hair
conditioners and hair colouring preparations. Besides being
surfactants and antistatic agents, the
alkyldimethylbenzylammonium compounds function as biocides in
various cosmetic and detergent products. The biocidal properties
are utilized, when ADMBAC are added to all-purpose or
specialized cleaning agents. No specific toxicokinetic studies
were identified for ADMBAC. Different homologues of ADMBAC
showed a moderate acute toxicity in experiments with rats and
mice (CIRP 1989, Zeiger et al. 1987).
ADMBAC are included in Annex I of the list of dangerous substances
of Council Directive 67/548/EEC with the following
classification: C8-18 ADMBAC are classified as Harmful with the
risk phrases R21/22 (Harmful in contact with skin and if
swallowed) and Corrosive (C) with R34 (Causes burns).
Amphoteric surfactants are surface-active compounds with both
acidic and alkaline
properties and include two main groups, i.e. betaines and real
amphoteric surfactants based on fatty alkyl imidazolines.
Amphoteric surfactants are used in personal care products (e.g.
hair shampoos and conditioners, liquid soaps, and cleansing
lotions) and in all-purpose and industrial cleaning
Betaines are primarily used in personal care products such as
hair shampoos, liquid soaps, and cleansing lotions. Other
applications include all-purpose cleaning agents, hand
dishwashing agents, and special textile
surfactants are easily absorbed in the intestine and are
excreted partly unchanged via the faeces without being
accumulated in the organism (SFT 1991). Betaines generally have
a low acute toxicity, e.g. LD50 values for cocoamidopropylbetain
(30% solution) by oral administration have been determined to
4,910 mg/kg body weight in rats (CIRP 1991).