Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2007-2-2
pubmed:abstractText
Ethoxylated alcohols, which are used as nonionic surfactants, are known to act as general narcotics in acute aquatic toxicity; that is, they behave in the same way as nonsurfactant unreactive organic chemicals. The toxicity of such chemicals is well predicted by quantitative structure-activity relationships based solely on the logarithm of the octanol/water partition coefficient (log P), which can be calculated from structure. In the present study, we have shown, using experimental results, that a similar approach can be used to determine the toxicity of ethoxylate/propoxylate alcohols (i.e., containing propoxy [PO] and ethoxy [EO] units). Our calculations indicate that use of the Roberts position-dependent branching factor in calculating the PO group contribution is more appropriate than the Leo and Hansch branch factor. The resulting log P value for a PO group is 0.01; that is, the overall contribution to the final log P value is close to zero. On this basis, it is predicted that nonionic surfactants containing both EO and PO groups should have the same molar toxicity as surfactants based on the same parent alcohol and with the same number of EO groups but with no PO groups. This prediction has been confirmed in Daphnia acute toxicity tests. Furthermore, both EO/PO and EO-only nonionics are found to fit the same linear relationship between log P and toxicity.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0730-7268
pubmed:author
pubmed:issnType
Print
pubmed:volume
26
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
68-72
pubmed:meshHeading
pubmed:year
2007
pubmed:articleTitle
Aquatic toxicity of ethoxylated and propoxylated alcohols to daphnia magna.
pubmed:affiliation
Safety and Environmental Assurance Centre, Unilever Colworth, Sharnbrook, Bedford MK44 1LQ, United Kingdom. jayne.roberts@unilever.com
pubmed:publicationType
Journal Article