Amines, C16-18 (even numbered)-alkyl , salts with phosphoric acid, mono- and di-C16-18 (even numbered) alkyl esters

Long-term toxicity to aquatic invertebrates

Description of key information

 The registered substance is an Alkyl phosphate and stearyl amine salts (EC = 952-252-4) are mainly composed by primary alkylamines (CAS 90640-32-7, UVCB) and phosphoric acid, octadecyl ester (CAS 39471-52-8, Multi-Constituent). Both elements present a long hydrogenated (saturated) carbon chain combinaison mono/diester phosphate with primary amine (16 to 18 carbon atoms). 

 

Regarding the other part of the salt, the Phosphoric acid, octadecyl ester (CAS 39471-52-8) the multiconstituant didn't show any chronic effects on Daphnia under a TG OECD 211 and GLP. The 21-day NOEL (reproduction) value, based on nominal loading rates, was determined to be greater than 100 mg/L loading rate WAF.

 

The key value for this endpoint was obtained with coco alkyl amine, tallow alkyl amine and oleylamine and corresponds to a NOEC reproduction of 0.013 mg/L for daphnia. These data have been used as read-across for the registered substance (for more details please see the read-across justification document attached in the Endpoint Study Reccord).

 

The key value is then converted to the corresponding value of the salt, resulting to a NOEC of about 0.034 mg/L (MW of Amines, tallow alkyl = 267 g/mol, MW of the registered substance = 710,7 g/mol (256 g/mol Primary alkylamine salt + 454,7 g/mol Phosphoric acid, octadecyl ester).

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Dose descriptor:

NOEC

Effect concentration:

0.034 mg/L

Additional information

 Data available for primary alkyl amines:

 

The chronic toxicity of coco alkyl amine, tallow alkyl amine and oleylamine to Daphnia magna was studied under comparable conditions by Noack (2002 a,b,c) using a semi-static test system according to the OECD Guideline 211 (Sept. 1998). Five test concentrations in the nominal concentration range between 0.013 mg/l and 0.5 mg/l were applied by diluting a stock dispersion (10 mg/l). Test solutions were renewed three times per week. As dilution water natural river water of agricultural background (middle reach of the river “Böhme”, lowerSaxony) was used. This river has been chosen due to its properties representing typical conditions of a German medium sized river. The concentration of suspended matter measured in the river water was in a range of 11.2 to 32.8 mg/l (mean value 18.4 mg/l) for coco alkyl amine and tallow alkyl amine and in a range of 10.0 to 26.2 mg/l (mean value 17.4 mg/l) for oleylamine. The content of humic acid amounted to 11.8 mg/l in all tests. A pre-treatment of the test vessels was not performed.

 

The concentrations of the active ingredient were determined in the old and new test media once per week in the stock solution, the highest test concentration of 0.5 mg/l and the control via GC-analysis. All samples were taken and analyzed without filtration to include test item adsorbed on suspended matter. In all tests the test item concentration decreased at the end of the test and recovery rates varied strongly. According to the test protocol the most probable reason for the decrease or incomplete recovery during the test was seen in adsorption on particulate matter and humic acids. The variation in the recovery rates were explained by small differences in the concentration of suspended matter. The results were therefore based on nominal concentrations representing the total exposure concentration (dissolved and adsorbed on humic acid / suspended matter).

 

Tab. 7.1.1.2.2-1:Daphnia magna repro test with natural river water-analytically verified concentrations of the highest test item concentration (0.5 mg/l) [mg/l]

Coco alkyl amine			Tallow alkyl amine			Oleylamine
Sample No.	new media (0 hours)	old media (3 days)	recovery	new media (0 hours)	old media (3 days)	recovery	new media (0 hours)	old media (3 days)	recovery
1	0.4	< LOQ	40%	0.2	< LOQ	20%	0.14	0.11	25%
2	0.2	< LOQ	20%	0.2	< LOQ	20%	0.22	< LOQ	22%
3	< LOQ	0.2	20%	0.3	0.2	50%	0.28	0.24	52%
4	< LOQ	< LOQ	0%	0.4	0.2	60%	0.24	0.23	47%
			mean 20%			mean 37.5%			mean 36.5%

 

           < LOQ    below limit of quantification

Referring to nominal concentrations a 21d-NOEC repro of 0.013 mg/l was derived for coco alkyl amine, tallow alkyl amine and oleylamine. When considering the validity of these studies, the following factors should be taken into account:

 

-       No measures were taken to prevent the loss of test substance by adsorption onto surface of the test vessels. Therefore, a quantification of the fraction lost by adsorption onto the glass ware is not possible.

 

-       Only the highest test concentration was analytically verified showing highly variable recovery rates. At concentrations around the NOEC even lower recovery rates have to be expected. Due to this, the exposure concentrations maintained during the studies are highly uncertain.

After correction for molecular mass of the salt, the 21d-NOEC for daphnia of the registered multi-constituent is considered to be 0.034 mg/L.