Toxicology of Industrial Compounds

Acute toxicity
In general, the acute oral toxicity of surfactants is low. The LD 50 values
typically range between several hundred and several thousand mg kg −1 of
bodyweight. This is of the same order of magnitude as for table salt
(Swisher, 1968). The most important effects are damage to the mucous
membranes of the gastrointestinal tract. High doses induce vomiting and
diarrhea (Weaver and Griffith, 1969). Surfactants exhibit significantly
higher toxicity when the gastrointestinal tract is by-passed through
intravenous injections. Even at very low concentrations, the interaction
with the membrane of erythrocytes leads to their destruction. Inhalation of
surfactant-containing dusts or aerosols in higher concentrations leads to
disturbances of the lung function (Coate et al., 1978). This effect can be
attributed to interactions with the surface active film that lines the vesicles
of the lung (Kissler et al., 1981). As with local compatibility, there are also
pronounced structure/activity relationships for acute toxicity. Gale (1953)
has investigated the acute toxicity of sodium alkyl sulphates from C 8 to C 18
and found the strongest effect for C 12 sulphate.
The anaesthetic properties of certain alcohol ethoxylates which can be
observed after intravenous application as well as after application to the
skin or the mucous membranes are remarkable. Ethoxylates of unbranched
primary alcohols with 9 ethylene oxide units were found to exhibit local
anaesthetic properties starting with an alkyl chain of C 8. The activity
increases with increasing chain length (Zipf and Dittmann, 1964).
Chronic toxicity
W.STERZEL 349
In order to exclude any adverse effects arising from the repeated exposure
against small amounts of surfactants over a prolonged period of time,
representatives of all important classes of surfactants were examined for
chronic toxic effects. In these tests, dosages of several thousands ppm were
administered over a period of up to 2 years. No observable effects were
detected with linear alkylbenzene sulphonates in 2 year studies with rats
using concentrations up to 0.5 per cent (feed) or 0.1 per cent (drinking
water) (Buehler et al., 1971). A sodium alkyl sulphate with an average
chain length of C12 was tolerated by rats up to 1 per cent in the feed for 1
year without any remarkable side effects (Fitzhugh and Nelson, 1948). C14 −16α-olefin sulphonates were applied over 2 years in a feeding study in
dosages up to 0.5 per cent without causing any remarkable effect (Hunter
and Benson, 1976). Analogous studies were reported for alcohol
ethoxylates and alkylphenol sulphates, which revealed no toxic symptoms
at doses up to 0.1 per cent and 1.4 per cent, respectively (Larson et al.,
1963; Siwak et al., 1982). Studies on cationic surfactants reported a noobservable-effect-level
of 0.25 per cent (Coulston et al., 1961). In all these