Alkyl ethoxylates: An assessment of their oral safety alone and in mixtures

Abstract

Some alkyl ethoxylates (AEs), nonionic surfactants which are widely used in industry and in household cleaning products, have been demonstrated to produce acute neuropharmacologic effects when sufficient systemic exposure is achieved. An investigative program was undertaken to characterize these effects and to evaluate the neuropharmacologic potential of some AEs with specific chainlengths, both commercially available materials and a pure homologue, following accidental oral exposure. Results show that even these AEs can be used safely in household cleaning products when their pharmacological properties are taken into consideration. Intraperitoneal administration of aqueous solutions of AEs to rats resulted in a progressive and reversible syndrome of central nervous system excitation and depression (ataxia, loss of righting) that resembled the induction of and recovery from general anesthesia. Oral administration to rats and mice of aqueous solutions of AEs, alone or in combination with anionic surfactants and ethanol, at concentrations that approach or exceed the maximum expected in household products (10–25%), rarely induced general anesthesia and then only at very high dose volumes (10 ml/kg and above). Based on these results and the fact that products containing the AEs evaluated usually produce emesis in humans, it is concluded that: (i) AE‐induced general anesthesia is not predicted to occur in humans following accidental oral exposure to products containing both the AEs and anionic surfactants, and (ii) general anesthetic effects in humans following accidental oral exposure to products containing fairly high levels of the specific AEs as the nonionic surfactant would be expected to occur only in cases of extremely high volumes of accidental ingestion (≥10 ml/kg).

Laundry Pack Exposures in Children 0–5 Years Evaluated at a Single Pediatric Institution

“…The primary ingredient of anionic detergents is ethoxylated alcohol, and ingestions are expected to cause gastrointestinal irritation, such as vomiting (16). While many of the children in this series had multiple episodes of emesis before presentation, all episodes had largely resolved by the time the patients were evaluated in the ED.…”

“…Only 6 patients received an anti-emetic and none of those received an intravenous fluid bolus. Animal studies have demonstrated lethargy and ataxia with high oral doses and the degree of ethoxylation is believed to correlate with toxicity (16,17). There has also been speculation that propylene glycol may be responsible for the observed CNS depression, but this seems unlikely given the amounts contained in these products.…”

Features reported after exposure to automatic dishwashing rinse aids

“…Although citric acid could potentially contribute to the reported features, it is typically present in rinse aids at concentrations 5% and therefore the features are more likely to be due to the surfactants. Some non-ionic surfactants, such as ethoxylated alcohols, have been shown to induce ataxia, loss of righting, respiratory depression, coma and death when administered intraperitoneally to rats, 6 although this exposure route may limit the relevance of these observations to human ingestion. Oral administration of non-ionic surfactants to rats and mice, either alone or in combination with anionic surfactants and ethanol, has caused sedation but only following the administration of large volumes of highly concentrated solutions.…”

“…Oral administration of non-ionic surfactants to rats and mice, either alone or in combination with anionic surfactants and ethanol, has caused sedation but only following the administration of large volumes of highly concentrated solutions. 6 The length of the alkyl chain does not appear to affect the toxicity of ethoxylated alcohols, although the degree of ethoxylation does. Compounds with ethylene oxide units between 5 and 14 are more toxic orally than those with less than 4 or more than 21 ethoxy units.…”

Laundry Detergent “Pod” Ingestions

“…A rat study demonstrated sedation effects from some alkyl ethoxylates, but the dose was relatively large; this does raise the possibility of a specific alkyl/ethoxylate chain length that causes significant sedation in humans beyond the general sedative effects of alcohols. 10 Recognition of the severe morbidity from laundry ''pod'' exposures resulted in a change in perception of the product's safety. Despite the European experience, there were no preparations for poison center surveillance or readiness with product codes when introduced to the US market.…”