1,3-diethenyl-1,1,3,3- tetramethyldisiloxane and its platinum(0) complexes

Additional ecotoxological information

Administrative data

Endpoint:

additional ecotoxicological information

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Remarks:

Solubility trials in ecotoxicity test media

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2016

Report date:

2016

Materials and methods

Principles of method if other than guideline:

The study consisted of solubility trials used to determine the maximum solubility of the test item under different treatment regimes, suitable for ecotoxicology tests, with separate analysis of platinum and the organic ligand.

GLP compliance:

no

Type of study / information:

Solublity trial for ecotoxicity studies

Test material

Test material information

Constituent 1

Reference substance name:

1,3-diethenyl-1,1,3,3- tetramethyldisiloxane and its platinum(0) complexes

EC Number:

701-315-2

IUPAC Name:

1,3-diethenyl-1,1,3,3- tetramethyldisiloxane and its platinum(0) complexes

Test material form:

liquid

Results and discussion

Any other information on results incl. tables

Table 1: Measured DVTMDS (organic ligand) concentrations in aqueous samples

Sampling date	Incubation time (h)	Decanted (µg/L)	Filtered (µg/L)	Centrifuged (µg/L)	Stock solution, shaken up (µg/L)
19_09_2016	0	48.76	<LOQ	2.25	-
20_09_2016	24	2.41	<LOQ	<LOQ	7.13
21_09_2016	48	<LOQ	<LOQ	<LOQ	6.12
22_09_2016	72	<LOQ	<LOQ	<LOQ	4.13
23_09_2016	96	<LOQ	<LOQ	<LOQ	2.74

Table 2 Measured Pt concentrations in aqueous samples

Sampling date	Incubation time (h)	Decamted Pt conc   (µg/L)	Filtered Pt conc   (µg/L)	Centrifuged Pt conc   (µg/L)
19_09_2016	0	45.164	3.901	6.474
20_09_2016	24	7.466	4.480	5.173
21_09_2016	48	6.554	5.377	9.432
22_09_2016	72	9.208	6.988	8.123
23_09_2016	96	7.025	5.561	6.188

Applicant's summary and conclusion

Conclusions:

Following 96 hour solubility trials, the organic ligand could only be detected in a very small number of samples at the start of the study and platinum could be detected at very low concentrations.

Executive summary:

96 hour solubility trials were conducted using test media representative of that used in ecotoxicity studies (Cu-free water with adjusted pH 6, as this reflects the lowest pH acceptable for an algae test with the highest expected solubility), and three methods of separation (filtration, centrifugation and settling by gravity) (Kotthoff 2016). Samples were taken at 24 hour intervals; platinum was analysed by ICP-MS and the organic ligand by GC-MS. The study does not follow a standard test guideline and is not GLP-compliant, but is used as supporting information for the ecotoxicity endpoints for this substance.

The organic ligand was only detected at levels >LOQ in one of the centrifuged samples at the start of the test, and was not detected in any of the filtered samples. Platinum was detected at low levels (3.901 - 9.43 µg/L for filtered and centrifuged samples). Concentrations were higher for the decanted samples, but this is believed to be due to the presence of undissolved test item.