Registration Dossier

Administrative data

Endpoint:
toxicity to microorganisms
Type of information:
experimental study
Adequacy of study:
supporting study
Study period:
nda
Reliability:
4 (not assignable)
Rationale for reliability incl. deficiencies:
other: GLP compliance is not noted. Method of experimentation is not a standard guidance. Method follows Krebs (1983).
Cross-referenceopen allclose all
Reason / purpose:
reference to same study
Reason / purpose:
reference to other study

Data source

Reference
Reference Type:
publication
Title:
Untersuchungen zur aquatischen toxizitat zinnorganischer verbindungen (Investigations on the Aquatic Toxicity of Organotin Compounds)
Author:
Steinhaeuser, K.G., W. Amann, A. Spaeth, and A. Polenz.
Year:
1985
Bibliographic source:
Vom Wasser. 65:203-214.

Materials and methods

Test guideline
Qualifier:
no guideline followed
Principles of method if other than guideline:
No other information provided.
GLP compliance:
not specified

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
Tetraoctyltin; no other information given
Specific details on test material used for the study:
Details on properties of test surrogate or analogue material (migrated information):
No information.

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
- Concentrations: Saturated solutions
- Sampling method: Sample solutions prepared in distilled water via vigorous shaking

Test solutions

Vehicle:
no
Details on test solutions:
PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: Saturated solutions created via vigorous shaking
- Eluate: None
- Differential loading: Not given
- Controls: Not described
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): No vehicle
- Concentration of vehicle in test medium (stock solution and final test solution(s) including control(s)): N/A
- Evidence of undissolved material (e.g. precipitate, surface film, etc): None given

Test organisms

Test organisms (species):
Photobacterium phosphoreum
Details on inoculum:
No information.

Study design

Test type:
not specified
Water media type:
not specified
Limit test:
no
Total exposure duration:
30 min
Post exposure observation period:
Unclear, not stated

Test conditions

Hardness:
Not given
Test temperature:
Not given
pH:
Not given
Dissolved oxygen:
Not given
Salinity:
Not given
Nominal and measured concentrations:
Only 30 min EC50 value given
Details on test conditions:
None given
Reference substance (positive control):
not specified

Results and discussion

Effect concentrations
Duration:
30 min
Dose descriptor:
EC50
Effect conc.:
0.63 µg/L
Nominal / measured:
meas. (not specified)
Conc. based on:
test mat.
Basis for effect:
other: inhibition of bioluminescence
Details on results:
None given
Results with reference substance (positive control):
None given
Reported statistics and error estimates:
No details available on statistics

Any other information on results incl. tables

No information.

Applicant's summary and conclusion

Validity criteria fulfilled:
not specified
Conclusions:
The EC50 for P. phosphreum is 0.63 µg/L by inhibition of phosphoresence.
Executive summary:

Owing to the low solubility, the active concentration is less than 1 mg/L for almost all organotin compounds having a demonstrated toxic effect on the test organisms. Basically, however, it should be noted that the determined saturation concentrations are only slightly higher than the toxic active concentrations in cetain cases.

The selected toxicity data from the literature, are often in good agreement with the test results achieved here, as regards the order of magnitude. However, certain publications have also published toxic active concentrations which are far beyond the solubility limits. Presumably, the accompanying analysis necessary for poorly soluble compounds was not performed in these studies; therefore it is to be assumed that a large portion of the test substance was present in undissolved or adsorbed and, thus, biologically unavailable form.

The following trends are clear from the results achieved thus far:

Due to their low solubility, the tetraorganotin compounds are to be evaluated less critically than the triorganotin compounds, despite their low EC values. It cannot be ruled out that the toxicity here is significantly influenced by more easily soluble trace impurities of triorganotin compounds, which accumulate in the aqueous phase. Thus, for tetrabutyltin, it can be observed that an increase in the measured amount from 50 mg/L to 1000 mg/L when preparing the aqueous solution increases the toxicity to luminescent bacteria (Photobacterium phosphoreum) by a factor of 22. Furthermore, in an aqueous solution of tetraphenyltin (measured amount 15 mg/L), one can detect 3.1 µg/L of triphenyltin, besides 30 µg/L of tetraphenyltin.