N,N-dimethyltetradecylamine N-oxide

Endpoint summary

Additional information

A summary of the available aquatic toxicity data for C14 AO and an analogue substance C12-14 AO is presented below:

Fish. Two reliable studies are available for C14 AO. In the key study, performed according to OECD TG 203, Zebra fish (Danio rerio) were exposed to the substance under semi-static conditions for 96 hours at nominal concentrations of 0, 0.23, 0.46, 0.92, 1.84 or 3.68 mg AO/L [Mark UE (1992)]. The 96-h LC50 was 2.4 mg AO/L. In the supporting study, also performed according to OECD TG 203, Zebra fish were exposed to the substance at 0, 2.5 or 25 mg/L AO for 96 hours [Jung R (1987)]. The 96-h LC50 was between 2.5 and 25 mg AO/L.

Data are available also for C12-14 AO. These data may be used to support the findings of the studies performed using C14 AO alone as the substance contains a significant amount of C14 AO and the remainder comprises an analogue substance with very similar chain length.

There are four reliable studies available for the C12-14 amine oxide. Iwan GR et al (1975) exposed Fathead minnow (Pimephales promelas) to C12-14 AO under static conditions for 96 hours. The LC50 (96 h) based on nominal concentrations of amine oxide ranged from 2.67 to 3.46 mg AO/L depending on the source and pH of the water used. In a supporting study Bluegill (Lepomis macrochirus) were exposed to C12-14 AO under static conditions for 96 hours. The LC50 value was reported as 3.13 mg AO/L [Macek & Sleight (1972)]. Exposure of rainbow trout (Oncorhynchus mykiss) to C12-14 AO under static conditions for 96 hours resulted in a LC50 of 12.6 mg AO/L [Dommrose AM (1987)], whilst exposure of zebra fish (Danio rerio) to C12-14 AO under static conditions resulted in a 96 -h LC50 of 3 -30 mg AO/L [Hoechst AG (1987)].

No long-term fish toxicity studies have been performed using C14 AO. Data are read across from C12-14 on the basis that the substance contains a significant amount of C14 AO and the remainder comprises an analogue substance with very similar chain length.

In a full life-cycle toxicity test (similar to EPA OPPTS 850.1500) fathead minnows (Pimephales promelas) were exposed to C12 -14 AO for 302 days under flow through conditions [Aquatic Environmental Services (1976)]. The nominal test concentrations were 0, 0.06, 0.13, 0.25, 0.50, and 1.0 mg AO/L. Mean measured concentrations were 82 -117% of nominal. Endpoints included survival, growth, and hatchability. The NOEC was 0.42 mg AO/L (mean measured concentration), based on reduced fry survival, reduced egg hatch, and occluded eyes in test fish. This was consistent with results of a preliminary 15 -day test, in which the NOEC was 0.495 mg AO/L.

Daphnia: One reliable study is available for C14 AO. In this study, performed according to OECD TG 202, groups of 5 Daphnia magna per concentration were exposed to C14 AO under static conditions for 48 hours at nominal test concentrations of 0, 5, 9, 16.2, 29.2 or 52.5 mg/L (equivalent to 0, 1.19, 2.13, 3.84, 6.92 or 12.44 mg AO/L). The 48-h EC50 based on nominal concentrations was 2.64 mg AO/L [Mark UE and Garttener-Arends ICM (1994)].

Data are available also for C12-14 AO. These data may be used to support the findings of the study performed using C14 AO alone as the substance contains a significant amount of C14 AO and the remainder comprises an analogue substance with very similar chain length.

Three reliable studies performed using Daphnia magna are available for C12-14 AO. All three studies were performed to OECD TG 202 under static conditions. The EC50 (48h) values (nominal) obtained were 3.1 mg AO/L [Noack M (2001)], 2.9 mg AO/L [Mark U & Meuwsen IJB (1990)] and 4.2 mg AO/L [Beneventi S (2005)]. 

No chronic daphnia toxicity studies have been performed using C14 amine oxide. Data are read across from C12-14 AO on the basis that this substance contains a significant amount of C14 AO and the remainder comprises an analogue substance with very similar chain length.

The long-term toxicity of C12-14 AO was evaluated in a 21 day survival and reproduction test withDaphnia magna, following the OECD 211 guideline [Maki AW (1977)]. Four replicates per concentration, 5 organisms per replicate, were tested in a flow-through system. Mean measured test concentrations were: 0, 0.08, 0.17, 0.34, 0.70, and 1.35 mg AO/L. Survival was monitored at 24 hours, 96 hours, 7 days, and daily thereafter. Reproduction was monitored beginning with the production of the first brood on day 7 or 8, and daily thereafter. EC50s were calculated by probit analysis. Results are based on the mean measured concentration of the amine oxide.

The 21-day NOEC was 0.70 mg AO/L, based on both survival and reproduction. The 21 day EC50 was 0.96 mg AO/L based on mortality. The 21-day EC50s, based on total young production, average brood size, and % days reproduction occurred, were 0.88 mg AO/L, 1.01 mg AO/L, and 1.04 mg AO/L, respectively.

Algae: One reliable study is available for C14 AO. In this study, performed according to OECD 201, Pseudokirchnerella subcapitata were exposed to C14 AO for 72 hours at nominal test concentrations of 0, 0.024, 0.047, 0.095, 0.190 or 0.379 mg AO/L [Mark UE (1992)]. The 72-h EbC50 was 0.095 mg AO/L. The 72-h ErC50 was 0.19 mg AO/L. No NOEC value was derived.

Data are available also for C12-14 AO. These data may be used to support the findings of the study performed using C14 AO alone as the substance contains a significant amount of C14 AO and the remainder comprises an analogue substance with very similar chain length.

Six reliable studies are available for C12-14 AO. In a study performed according to OECD TG 201 under GLP [Ginkel & Kroon (1990)] Pseudokirchnerella subcapitata were exposed to C12-14 AO under static conditions for 72 hours at nominal concentrations of 0, 0.020, 0.039, 0.078, 0.155 or 0.31 mg AO/L. The ErC50 (72 h) was 0.266 mg AO/L. In three supporting studies performed according to OECD TG 201 Pseudokirchnerella subcapitata were exposed to C12-14 AO for 72 hours under static conditions. ErC50 values of 0.159 mg AO/L [Brill J (2010)], 0.12 mg AO/L [Hanstveit & Oldersma (1997)] and 0.082 mg AO/L [Hanstveit & Oldersma (1996)] were reported. Exposure of Chlorella vulgaris to C12-14 AO for 72 hours under static conditions in accordance with OECD TG 201 resulted in an ErC50 of 1.7 mg AO/L [Vreys (2003)], whilst exposure of Desmodesmus subspicatus to C12-14 AO for 72 hours under static conditions in accordance with OECD TG 201 resulted in an ErC50 of 0.25 mg AO/L [Scheerbaum (2000)].

According to the Guidance to Regulation (EC) No 1272/2008 on classification, labelling and packaging (CLP) of substances and mixtures, page 408, when larger data sets (four or more values) are available for the same species, the geometric mean of toxicity values may be used as the representative toxicity value for that species. Taking this guidance into account, based on the studies performed using C12-14 AO, the geometric mean 72 -h ErC50 for Pseudokirchnerella subcapitata is 0.143 mg AO/L.

The toxicity of C12-14 AO to algae was evaluated in a 28 -day freshwater periphyton microcosm assay [Belanger SE (1999)]. The microcosm was composed of a complex consortia of bacterial, cyanobacterial, algal, and fungal species, and included 110 taxa of algae (notably 87 diatom, 12 green, 7 blue-green, 2 euglenoid, 1 chrysophyte and 1 red). Two substrates (tiles, cobbles) were naturally colonised for 5 weeks in high quality flowing streams/rivers in. The periphyton-colonised tiles & cobbles were then brought into the laboratory and placed in a 28 day flow through test of the C12-14 AO. Periphyton communities were exposed to 0, 6.25, 12.5, 25, 50 or 100 µg AO/L (nominal) for 28 days. Mean measured concentrations were 4.3 (control), 8.6, 9.2, 16.1, 33.1 or 67.1 µg AO/L. There were clear location (i.e. colonisation stream) and substrate effects in this study. Tile and cobble were substantially different, as were the Little Miami River and Big Derby Creek communities. Adverse responses were absent by day 28 in all three communities. There were significant increases in some endpoints at the 2 highest test concentrations (50, 100 µg/L, nominal), but there were no significant decreases (adverse effects) for any endpoint. The No-Observed Effect Concentration (NOEC) of the substance to the periphyton community was determined to be > 67 µg AO/L, the highest test concentration evaluated (mean measured concentration).

Based on the very similar results obtained with Pseudokirchnerella subcapitata in the acute tests performed with C14 and C12-14 AO it is considered valid to read across the result of the periphyton study to C14 AO.

Microorganisms: No reliable studies are available for C14 AO. Data are read across from C12-14 AO on the basis that this substance contains a significant amount of C14 AO and the remainder comprises an analogue substance with very similar chain length.

Two reliable studies are available for C12 -14 AO. In the key study Kolvenbach (1990) exposed Pseudomonas putida to C12-14 AO for 18 hours in a Bringmann-Kuehn test. The EC10, based on reduction in growth rate, was 24 mg AO/L.

Sediment-dwelling organisms:No studies are available, however risk characterisation using the equilibrium partitioning method indicates that the risk to sediment dwelling organisms is adequately controlled and there is no need for further refinement of the assessment through testing.