Chemwatch: 4883-43
Page 12 of 14
Version No: 3.1.1.1
Issue Date: 12/20/2013
Print Date: 07/05/2016
Fido's Herbal Shampoo
are also degraded quite rapidly, but multiple branchings of the alkyl chain considerably reduce the rate and extent of primary biodegradation. There are
numerous studies confirming the aerobic biodegradability of AS, and linear primary AS exceeds all other anionic surfactants in the rate of primary and
ultimate biodegradation. Also secondary AS are normally readily biodegradable as, e.g., the oxygen uptake from biodegradation of a linear secondary
C10-13 AS corresponded to 77% ThOD in 22 days. Some highly branched AS being poorly primary biodegradable may also resist ultimate biodegradation.
Both linear and 2-alkyl-branched primary AS are degraded to a high extent under anaerobic conditions.
AS are generally considered to have a low potential for bioconcentration in aquatic organisms
For alkane sulfonates: Alkane sulfonate anionics (SAS) undergo rapid primary biodegradation with Methylene Blue Active Substance (MBAS) removal
higher than 90% within a few days. Removal of 96% were seen in the OECD screening test for primary biodegradation. In activated sludge simulation
tests, 96% of C10-18 SAS was removed, while the parent C13-18 SAS was removed by 83-96%.
Alkyl sulfonates are not degraded under anoxic conditions
For alpha-olefin sulfonates: alpha-Olefine sulfonates (AOS) AOS undergo rapid primary biodegradability with methylene blue active substances ( MBAS)
removal between 95 and 100% in 2 to 8 days in river water and inoculated media. The ultimate biodegradability of AOS exceeds the pass requirements in
OECD 301 tests for ready biodegradability. report 85% DOC removal in the modified OECD screening test, 85% ThOD in the closed bottle test, and
65-80% ThCO2 in the Sturm test. In activated sludge simulation tests, AOS was removed by 100% MBAS and 88% DOC. The alkene sulfonates and
hydroxyalkane sulfonates in commercial AOS are both ultimately biodegraded as approximately 84% ThCO2 was obtained during degradation of C14,
C16, and C18 within 27 days, whereas the corresponding 3-hydroxyalkane sulfonates were degraded by approximately 86% under the same conditions.
AOS are not readily degradable under anaerobic conditions Reports indicate a range of 31% to 43% MBAS removal under anoxic conditions indicating
primary biodegradation
Ecotoxicity:
The aquatic toxicity is influenced by a number of parameters, the length of the alkyl chain being most important. The pH and temperature of water bodies
can affect the EC/LC50 values for compounds that contain ammonium ions.
The most sensitive trophic level in tests on the toxicity of alkyl sulfates were invertebrates, followed by fish. Algae proved to be less sensitive. The key
study for the aquatic hazard assessment is a chronic test on Ceriodaphnia dubia, which covers a range of the alkyl chain length from C12 to C 18. A
parabolic response was observed with the C14 chain length being the most toxic (NOEC = 0.045 mg/l).
For alkyl sulfates: Fish LC50 (96 h): fathead minnow - fry 10.2 mg/l; juvenile 17 mg/l; adult 22.5 mg/l; rainbow trout 4.6 mg/l (static)
The aquatic toxicity of AS seems to increase with increasing alkyl chain length. This has been shown for daphnids and for some fish species. An overall
comparison of the acute toxicity between the primary and secondary AS shows only minor differences in the toxicity, although only a few studies for
comparison are available.
The available data describing the toxicity of AS towards algae indicate that the lowest EC50 values range between 1 and 10 mg/l for C12 AS
The toxicity of AS towards invertebrates has mainly been examined in tests with Daphnia magna. The acute toxicity of AS to Daphnia magna increased
with increasing alkyl chain length. It has been shown that during degradation of C12 AS, the toxicity first increased to a maximum after 30 hours and then
fell to almost a negligible value. The increase in toxicity was explained by the formation of the more toxic dodecanoic acid which is rapidly transformed to
other and less toxic metabolites.
Studies showed that the 24 h-LC50 values for killifish in distilled water decreased by a factor of about 10 when the alkyl chain was increased by two
carbon atoms. C16 was 10 times more toxic than C14, which was about 10 times more toxic than C12 AS.
The toxicity of AS to fish has been demonstrated to increase with increasing alkyl chain length as also seen in studies with Daphnia magna. The acute
toxicity on Daphnia magna has been determined for chain length C8-C14. Results were comparable to alkyl sulfates in the range between C8 and C10,
while C12 and C14 are significantly less toxic. Chronic data obtained for C12 alkane sulfonate sodium and C12-alkyl sulfate sodium with the
rotifer Brachionus calicyflorus similarly show that alkane sulfonates might be less toxic than alkyl sulfates. C16 and C18 alkane sulfonates are assumed
to exhibit the same toxicity than alkyl sulfates of comparable chain lengths. No data are available concerning the toxicity of alkane sulfonates on fish
and algae. However, a similar toxicity might be assumed because of structural and physico-chemical similarities between the three subcategories
Whereas most correlations between AS structure and toxicity show an increasing toxicity with increasing alkyl chain length, the budding in Hydra
attenuata was apparently more affected by C10 AS than by C12, C14, and C16 AS. The authors suggested that the decrease in toxicity with increasing
alkyl chain length was attributable to reduced solubility in water
Tests on the toxicity to microorganisms were only conducted with alkyl sulfates as test substances. A test on the inhibition of respiration of activated
sludge resulted in an 3 h-EC50 of 135 mg/l (nominally). The lowest effect value for protozoa was obtained from a test on Uronema parduczi using
C12-alkyl sulfate sodium - the 20 h-EC5 was 0.75 mg/l.
Experimental test results on benthic organisms in a water-sediment system are not available. However, due to sediment-water partitioning coefficients Kd
< 350, no significant risk for organisms in this compartment is to be expected.
Data indicate that toxic effects on soil organisms might only be expected at high concentrations for alkyl sulfates. Toxicity of alkane sulfonates and
alpha-olefin sulfonates can not be assessed because test results for terrestrial organisms are not available.
For alpha-olefin sulfonates, reliable short-term tests on fish, invertebrates and algae are available. The results indicate that toxicity is increasing as the
alkyl chain length increases. The lowest available effect value is the 96 h-LC50 = 0.5 mg/l, determined in tests on Oryzias latipes, Rasbora
heteromorpha and Salmo trutta
Algae show toxic effects to growth when exposed 10-100 mg/l for C14-18 AOS.
EC50 values for Daphnia magna have been determined within the range 5-50 mg/l for C14-18 AOS . Another study with Daphnia magna, showed EC50
values of 16.6 mg/l for C14-16 AOS and 7.7 mg/l for C16-18 AOS.
Studies performed with fish show that the higher homologues of AOS are more toxic than the lower ones. This has been illustrated for different fish
species (LC50 (96 h) range 0.5-5.3 mg/l)
For alkane sulfonates: The toxicity of various SAS homologues was determined in tests with Chlamydomonas variabilis. After 24 hours of exposure at 20
C, there was a tendency to an increased toxicity with increasing chain length. The EC50 values were 125 mg/l for C10.3, 74.9 mg/l for C11.2, 32.4 mg/l
for C14, 15.8 mg/l for C15, 9.42 mg/l for C16, 3.93 mg/l for C17, 3.71 mg/l for C18.9, and 8.47 mg/l for C20.7.
SIDS Initial Assessment Profile
Environmental and Health Assessment of Substances in Household Detergents and Cosmetic Detergent Products, Environment Project, 615, 2001.
Torben Madsen et al: Miljoministeriet (Danish Environmental Protection Agency
DO NOT discharge into sewer or waterways.
Persistence and degradability
Ingredient
Persistence: Water/Soil
Persistence: Air
water
LOW
LOW