LINEAR ALKYLBENZENE SULFONATE (LAS) - UNEP Chemicals

OECD SIDS LINEAR ALKYLBENZENE SULFONATE (LAS)
Conservation Service soil type designation, by Howard Laboratories, Dayton,
Ohio
Organic Carbon: 1.4 - 50%
Soil pH: 4.9 - 8.4
Cation exchange
capacity: 0.15 meg/100 g soil dry weight
Microbial biomass: Activity in dpm/h/gdw soil varied from 11,327 to 51,683
Dissipation time: DT50 : 1.1 - 3.7 days
Method: other: described in reference
GLP: Yes [ ] No [ ] ? [X]
Test substance: C13 LAS (CAS #26248-24-8); activity 98%
Remarks: Half-lives ranged from 1.1 to 3.7 days (mineralization). First order
dissipation rate constants ranged from 0.14 - 0.63/day. Mineralization
occurred without a lag-period in every soil tested. Cycles of wetting and
drying in the lab prior to testing resulted in more rapid and extensive
mineralization. Community microbial activity did not correlate with rate or
extent of mineralization. Microbial communities have indigenous ability to
degrade low LAS concentrations, the ability is present in a wide array of soil
types from various locations.
1. Soil Alpine, sand, pH 5.5, CEC 0.15, TOC 50 (mg/g)
2. Soil Bonnell, sandy loam, pH 8.4, CEC 29, TOC 31.6
3. Soil Brashear, silt loam, pH 7.7, CEC 37, TOC 24.9
4. Soil Eden, silt loam, pH 7.4, CEC 33, TOC 45.1
5. Soil Eden, loamy sand, pH 6.1, CEC 41, TOC 19.6
6. FL soil, sand, pH 4.9, CEC 6.3, TOC 13.8
7. GA soil, loamy sand, pH 4.9, CEC 15.5, TOC 1.4
8. Soil Huntington, loam, pH 7.3, CEC 24, TOC 20.1
9. Soil Lakin, loam, pH 6.5, CEC 24, TOC 34.6
10. Soil Pate, silt loam, pH 7.7, CEC 46, TOC 48.0.
Reference: Knaebel, D.B., Federle, T.W. and Vestal, J.R. 1990. Mineralisation of linear
alkylbenzene sulfonate (LAS) and linear alcohol ethoxylate (LAE) in 11
contrasting soils. Envir. Toxicol. Chem. 9:981-988.
Reliability: 2 Valid with restrictions
(c)
Type : Field trial [X]; Laboratory [ ]; Other [ ]
Radiolabel: Yes [ ] No [X] ? [ ]
Dissipation time: DT50 : 7 - 22 days
Results: In fields not recently spread with sludge, the concentrations of LAS found in
the sludge amended soil were generally less than 1 mg/kg. This represents
an estimated loss of LAS from soil of >98%. In fields recently spread, the
concentrations in soil are in the range of