Alcohols, C11-15-secondary, ethoxylated

Endpoint summary

Description of key information

Table 1: Matrix of data for Softanol 30 and the family of alcohol ethoxylates (Aquatic toxicology profile)

Study	Softanol 30 (REACH dossier) secondary C11-15AE3	Alcohol ethoxylates (Hera, 2009)
Acute toxicity fish	Rainbow trout 96h-LC50= 1.53 mg/L (nominal) At 1.03 mg/L and higher concentrations and comprised of lethargy, darkened pigmentation, hyperventilation, loss of orientation and immobility.	Brown trout 96h-LC50= 0.4 mg/L of C16-18AE14(primary AE) Fathead minnow 96-hr LC50 values ranged from 0.48 mg/L of C12-15AE7to 3.6 mg/L of C12-15AE12(primary AE) Fathead minnow 24-hr LC50 values of 2.8-2.9 mg/L (secondary AE) and 1.8 mg/L (primary AE)
Long term toxicity fish	Chronic fish QSAR EC10= 0.87 mg/L	Fathead minnow larvae NOEC for survival = 0.18 mg/L C14-15AE7Fathead minnow NOEC for survival and reproduction= 0.32 mg/L of C12-15AE6.5in a 1-year study
Acute toxicity aquatic invertebrates	Daphnia magna48-hr LC50=5.66mg/L (immobilisation) The ‘no-observed effect loading rate’ of Softanol 30 with Daphnia magnawas 3.2 mg/L.	Daphnia magna Secondary AE: 48-hr LC50 values of >5 and 13mg/L of C11-15AE7and C11-15AE9 Primary AE: 48-hr LC50 values of 2.3 – 2.4mg/L of C12-14AE6.3and C12-14AE7.4
Long term toxicity aquatic invertebrates	Chronic Daphnia magna QSAR NOEC= 0.2 mg/L	Daphnia magna21-day NOEC reproduction = 0.24 mg/L of C12-15AE6.3orC14-15AE7
Toxicity to Algae	S. capricornutum 72h- EbC50=1.03mg/L 72h- ErC50=2.01mg/L “no observed effect loading rate” (NOELR) for area under the growth curve, growth rate and yield for Softanol 30 was 0.305 mg/L.	S. capricornutum(green algae) Secondary AE: EC50 growth rate values of 52 and 56 mg/L of C11-15AE7and C11-15AE9 Primary AE: EC50 growth rate values of 0.09 to 10mg/L of C14-16AE6and C12-14AE13 EC10 growth rate values range from 0.03 mg/L (C12AE2) to 9.791 mg/L (C8-10AE5) EC10 growth rate values of 0.137 mg/L for C12-14AE7and 0.204 mg/L for C12-13AE3
Sediment toxicity	Chronic Daphnia magna QSAR NOEC= 0.2 mg/L	Chironomus tentans Survival EC10values of 3.635 mg/l of C9-11AE6

Short-term toxicity to fish

The 96-hour LL₅₀value for Softanol 30 with rainbow trout was 1.53 mg/L WAF, with 95% confidence limits of 1.03 and 2.27mg/L.

The “no observed effect loading rate” (NOELR) was 0.470 mg/L WAF.

Long term toxicity to fish

QSAR value: Fish survival EC10 = 10^{-0.280 log Kow+1.90}= 2.61 μmol/L (0.87 mg/L)

Short-term toxicity to aquatic invertebrates

The 24 and 48 hour EL50 was 5.66 mg/L for D.magna and the no observed effect loading rate (NOELR) was 3.2 mg/L

Long-term toxicity to aquatic invertebrates

QSAR value: Daphnia NOEC= 10^{-0.803 log Kow+4.078} = 0.66μmol/L (0.20 mg/L)

Toxicity to aquatic algae and cyanobacteria

The 72-hour E_rL₅₀of algae exposed to the test substance was determined to be 2.01 mg/L.

Toxicity to aquatic plants other than algae

No data available. No data required.

Toxicity to microorganisms.

Activated Sludge Respiration Inhibition Test

EC20 was calculated to be 39 mg/L (95% confidence limits, 5.1 to 162 mg/L).

Toxicity to other microorganisms

No data available. No data required.

ConclusionThe most sensitive trophic level is aquatic invertebrates (Daphnia). Toxicity at the three tropic levels, fish, aquatic invertebrates and aquatic plants occurred at similar concentrations of test substance in test media.

Additional information

Acute fish, acute aquatic invertebrates, alga and microorganism toxicity studies have been performed with softanol. Under Annex IX of the REACH regulation, data on long term toxicity to fish, Daphnia and toxicity to sediment dwellers is required. Acute and chronic toxicity evaluation to aquatic organisms have been performed in laboratory and mesocosms with other linear primary, linear secondary and branched ethoxylated alcohols using fish, aquatic invertebrates and freshwater algae (Talmage, 1994; Hera, 2009).

 

Short-term toxicity to fish

One study is available and valid. In a 96 -h acute toxicity study,rainbow trout (Oncorhynchus mykiss)(7/group) were exposed to Softanol 30 at nominal concentrations of 0 (control), 0.0970, 0.213, 0.470, 1.03, 2.27 and 5 mg/L as Water Accommodated Fractions (Huntingdon Life Sciences, 2010, report PLZ0026. Mortalities were observed at the top two levels, 2.27 and 5 mg/L.The 96-hour LL50value for Softanol 30 with rainbow trout was 1.53 mg/L WAF, with 95% confidence limits of1.03 and 2.27mg/L.The “no observed effect loading rate” (NOELR) was 0.470 mg/L WAF.This toxicity study is classified as acceptable and fully satisfies the guideline requirement for short-term toxicity to fish.

 

Long term toxicity to fish

This study is proposed to be waived. A weight of evidence assessment shows that toxicity to fish of ethoxylated alcohols is related to their chemical structure. A chronic QSAR for P. promelas was derived following the method of Boeije et al (2006) for AEs was used to calculate an EC10 value for softanol.

Fish survival EC10 = 10^{-0.280 log Kow+1.90}= 2.61 μmol/L (0.87 mg/L)

 

Short-term toxicity to aquatic invertebrates

One study is available and valid. The 48–h-acute toxicity of Softanol 30 to Daphnia magna was studied under static conditions (Huntingdon Life Sciences Ltd, 2010 report PLZ0025).  Daphnids were exposed for 48 hours to WAFs of Softanol 30, prepared from aqueous mixtures with initial nominal concentrations (loading rates) of 0.1, 0.32, 1.0, 3.2 and 10 mg/L. Mortality/immobilization and sublethal effects were observed after approximately 24 and 48 hours. The 24 and 48 hour EL50 was 5.66 mg/L and the no observed effect loading rate (NOELR) was 3.2 mg/L This study is classified as acceptable and satisfies the guideline requirements for an acute toxicity study with freshwater invertebrates.

 

Long-term toxicity to aquatic invertebrates

This study is waived.

A weight of evidence assessment shows that toxicity of ethoxylated alcohols to Daphnia is related to their chemical structure. A chronic QSAR for D. magna was derived for AEs following the method of Boeije et al (2006) and was used to calculate an NOEC value for softanol.

Daphnia NOEC= 10^{-0.803 log Kow+4.078} = 0.66μmol/L (0.20 mg/L)

 

Toxicity to aquatic algae and cyanobacteria

One study is available and valid. The effects of Softanol 30 on the growth of green algae (Pseudokirchneriella subcapitata)was studied under mixed population conditions (Huntingdon Life Sciences Ltd, 2010 report PLZ0024). Triplicate algal cultures, with an initial cell density of 1 x 104/mL, were exposed to water accommodated fractions (WAFs) of Softanol 30 prepared from aqueous mixtures with initial nominal concentrations (loading rates) of 0.977, 3.13 and 10 mg/L. The 72-hour ErL50of algae exposed to the test substance was determined to be 2.01 mg/L. This study is classified as acceptable and satisfies the guideline requirements for a growth inhibition study with aquatic plants.

 

Toxicity to aquatic plants other than algae

No data available. No data required.

 

Toxicity to microorganisms

The effect of Softanol 30 on the respiration rate of activated sludge was assessed by the methods detailed in OECD Test Guideline 209, ‘Activated Sludge, Respiration Inhibition Test’ and EC Directive 88/302, Method C.11, ‘Biodegradation - Activated Sludge Respiration Inhibition Test’ (Huntingdon Life Sciences Ltd, 2010, PLZ0027) Samples of activated sludge, fed with synthetic sewage, were exposed to dilutions of the test substance (concentrations of 10, 30, 100, 300 and 1000 mg/L. for three hours. The three-hour EC50 for Softanol 30 was calculated to be 824 mg/L (95% confidence limits, 355 to 2680 mg/L). The EC20 was calculated to be 39 mg/L (95% confidence limits, 5.1 to 162 mg/L). The EC80 could not be calculated.

 

Toxicity to other microorganisms

No data available. No data required.

 

Conclusion: The most sensitive trophic level is aquatic invertebrates (Daphnia magna). Toxicity at the three tropic levels, fish, aquatic invertebrates and aquatic plants occurred at similar concentrations of test substance in test media.