Reaction mass of Octadec-9-en-1-yl ammonium di-n-hexyl phosphorodithioate and Octadec-9-en-1-yl ammonium mono- and di-butylphosphate

Endpoint summary

Description of key information

Adequate OECD guideline studies are available for EC 434-280-4. However, no analytical measurements were conducted and therefore, these studies are Klimisch coded as 2. Supporting information is attached that further evaluates the aquatic potential and validates the studies with EC 434-280-4, including that the level of toxicity observed is accurate and are appropriate to use for the risk assessment.

As further detailed in the attached document (including references, which are also attached in Section 12), EC 434-280-4 will dissociate immediately in water to the starting materials:

1. (Z)-octadec-9-enylamine (CAS 112-90-3): Reliable data for all 3 species


2. Dibutyl hydrogen phosphate (CAS 107-66-4): Reliable data for all 3 species


3. Butyl dihydrogen phosphate (CAS 12788-93-1: Reliable data for all 3 species


4. O,O-dihexyl hydrogen dithiophosphate (CAS 78-64-8; AKA Di-n-hexyl dithiophosphoric acid): There is only limited data for analogs that have alkyl side chains bracketing dihexyl hydrogen dithiophosphate (including a C4 and C8 dialkyl dithiophosphate). In addition, there is data available for zinc dialkyl dithiophosphates (ZDDPs) that are used as further evidence to evaluate the aquatic toxicity. ZDDPs have the same functional group but are in a zinc complex that is expected to dissociate in water. Based on this analog data, it is expected that the acute aquatic toxicity is in the 1-100 mg/L range. This data is sufficient to determine that it is less hazardous than (Z)-octadec-9-enylamine, which is critical because if (Z)-octadec-9-enylamine is the most hazardous constituent, then it will drive the risk assessment.

The following table compares the aquatic toxicity data of the dissociation products with EC 434-280-4 and demonstrates that (Z)-octadec-9-enylamine is indeed the most hazardous to aquatic organisms (see attached justification for further information, including references).

 

Endpoint	EC 434-280-4	(Z)-octadec-9-enylamine (112-90-3)	Alkyl phosphate esters	Alkyl dithiophosphate esters
Acute Toxicity to Fish (OECD 203)	96-hr LL50= 7.3 mg/L (nominal loading rates – WAF) 96-hr NEOL = 1.8 mg/L (WAF)	96 hr LC50 = 0.11 mg/L	72 hr LC50 > 100 mg/L	Toxicity estimated to be in the 1-100 mg/L range based on read across
Acute Toxicity to Invertebrates (OECD 202)	48-hr EL50= 0.15 mg/L (WAF) 48-hr NOEL = 0.090 mg/L (WAF)	48 hr EC50 = 0.011 mg/L	48 hr EC50 > 100 mg/L
Acute Toxicity to Algae (OECD 201)	Cell density 96-hr EL50= 0.13 mg/L (WAF) Growth rate 96-hr EL50= 0.17 mg/L (WAF) NOEL = 0.050 mg/L (WAF)	72 hr EC50 = 0.46 mg/L	72 hr EC50 > 100 mg/L

 

To confirm that the calculated PNECs for EC 434-280-4 are reasonable and protective, the calculated PNCECs are compared with those for primary alkyl amines evaluated in the EU Risk Assessment Report (2008) and the REACH registration for EC 627-034-4. (Z)-octadec-9-enylamine (112-90-3) is the most hazardous to aquatic species of the starting materials and is, therefore, the most relevant.

 

Endpoint	PNEC EC 434-280-4	PNEC CAS 112-90-3 (from EU RAR, 2008)	REACH registration for EC 627-034-4
PNEC aquatic (freshwater)	0.15 µg/L	0.26 µg/L	0.26 µg/L
PNEC aquatic (marine)	0.015 µg/L	0.26 µg/L	0.026 µg/L
PNEC microorganism	10 mg/L	550 µg/L	550 µg/L
PNEC sediment (freshwater)	23 µg/kg wet sediment	39 µg/kg wet sediment	3.76 mg/kg sediment
PNEC sediment (marine)	2.3 µg/kg wet sediment	39 µg/kg wet sediment	0.376 mg/kg sediment
PNEC soil	137 µg/kg wet soil	2.0 mg/kg dry weight	10 mg/kg soil

 

As seen in the table, the PNECs for EC 434-280-4 are more conservative than (Z)-octadec-9-enylamine. As (Z)-octadec-9-enylamine is the most hazardous dissociation product for aquatic toxicity, it would be reasonable to adopt the same PNECs as this would be protective of the entire substance upon dissociation. However, as the RCRs are already < 0.01 for all environmental endpoints using the more conservative PNECs calculated from the EC 434-280-4 data, this further demonstrates that the environmental risks are managed, and that no additional aquatic toxicity testing is required.

Following is a summary of the studies on EC 434-280-4:

Short term toxicity to fish

The 96 -hour LL50 based on nominal loading rates was 7.3 mg/L loading rate WAF with 95% confidence limits of 6.9 -7.7 mg/l loading rate WAF. The No Observed Effect Loading Rate was 1.8 mg/l loading rate WAF.

 

Samples sof the control, 1.0 and 10 mg/L loading rate WAFs were taken at 0 (fressh media) and 24 hours (old media) for Total Organic Carbon (TOC) analysis. Given the beackground level of carbon in the control vessels and also the low level of carbon in the test vessels, it was considered that all the results were around the limit of quantitation of the analytical method and hence did not provide defintive evidence of stbility of the test preparrations.

 

Information provided by the Sponsor indicated that the test material was a mixture of components. Therefore, given that the toxicity cannot be attributed to a single component of a mixture of components but to the test material as a whole, the results were based on nominal loading rates only.

 

Short-term toxicity to aquatic invertebrates

The 48 -hour EL50 for the test material to Daphnia magna based on nominal loading rates was 0.15 mg/L loading rate WAF with 95% confidence limits of 0.14- 0.18 mg/l loading rate WAF. The No Observed Efffect Loadung Rate was 0.090 mg/l loading rate WAF.

 

Samples sof the control, 0.050 and 5.0 mg/L loading rate WAFs were taken at 0 (fresh media) and 24 hours (old media) for Total Organic Carbon (TOC) analysis. Given the beackground level of carbon in the control vessels and also the low level of carbon in the test vessels, it was considered that all the results were around the limit of quantitation of the analytical method and hence did not provide defintive evidence of stbility of the test preparrations.

 

Information provided by the Sponsor indicated that the test material was a mixture of components. Therefore, given that the toxicity cannot be attributed to a single component of a mixture of components but to the test material as a whole, the results were based on nominal loading rates only.

 

Toxicity to aquatic algae and cyanobacteria

 

Exposure of Pseudokirchneriella subcapitata to the test material gave an EbL50 (72 h) value of 0.15 mg/L loading rate WAF, an EbL50 (96 h) value of 0.13 mg/L loading rate WAF and an ErL50 (0 -96 h) value of 0.17 mg/l loading rate WAF. The No Observed Effect Loading rate was 0.050 mg/Lloading rate WAF.

 

Total Organic Carbon (TOC) analysis of the control, 0.050 and 0.80 mg/l loading rate WAS test preparations were performed at 0 and 96 hours. Given the beackground level of carbon in the control vessels and also the low level of carbon in the test vessels, it was considered that all the results gave no evidence of the presenvce of the test material in the WAF.