Registration Dossier

Administrative data

Endpoint:
additional ecotoxicological information
Type of information:
experimental study
Adequacy of study:
supporting study
Study period:
21 January 2008 to 1 February 2008.
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Recently conducted GLP compliant study using the most recent test methods
Cross-reference
Reason / purpose:
reference to same study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2008
Report Date:
2008

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
other: determination of environmental endocrine disruption
Principles of method if other than guideline:
Based on a proven recombinant yeast screen assay for the determination of environmental endocrine disruption (Routledge and Sumpter, 1996).
GLP compliance:
yes (incl. certificate)
Type of study / information:
A study was performed to assess the oestrogenic activity of the test material using a recombinant yeast screen assay. The method was based on a proven recombinant yeast screen assay for the determination of environmental endocrine disruption (Routledge and Sumpter, 1996).

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
Sponsor's identification: JKY-214
Description: white powder
Batch number: RM05-58
Date received: 31 December 2007
Storage conditions: room temperature in the dark

Results and discussion

Any other information on results incl. tables

RESULTS

 

Range-finding Test

 The mean absorbance values for the test material and associated solvent control cultures are given in Table 1 below:

 

Table 1 - Mean Absorbance Values for the Test Material and Associated Solvent Control Cultures in the Range-finding Test

 

 

Nominal Concentration (mg/l)

Absorbance (540 nm)

 

 

Test Material

Solvent Control

0.000010

1.163

1.280

0.00010

1.138

1.199

0.0010

1.147

1.175

0.010

1.141

1.197

0.10

1.157

1.214

1.0

1.130

1.198

10

1.155

1.223

100

1.155

1.216

 

The results showed no oestrogenic activity at all the test concentrations tested. Based on this information, a single test concentration of 100 mg/l (twenty four replicate wells per plate) was selected for the definitive test.

 

In accordance with current regulatory guidelines for the environmental classification of chemicals, it was considered unnecessary and unrealistic to test at concentrations in excess of 100 mg/l in order to obtain a significant response in the yeast screen assay.

 

Definitive Test

 

Mean absorbance values for the positive control materials, test material and associated solvent control cultures are given in Tables 2 to 4 below:

Table 2 - Mean Absorbance Values for17β-estradiol and Associated Solvent Control Cultures in the Definitive Test

 

 

Nominal Concentration (mg/l)

Absorbance (540 nm)

 

 

17β-estradiol

Solvent Control

1.33 x 10 -6

1.243

1.190

2.66 x 10 -6

1.251

1.237

5.32 x 10 -6

1.264

1.260

1.06 x 10 -5

1.290

1.240

2.13 x 10 -5

1.363

1.210

4.26 x 10 -5

1.486

1.217

8.52 x 10 -5

1.695

1.268

1.70 x 10 -4

2.026

1.227

3.41 x 10 -4

2.415

1.234

6.81 x 10 -4

2.635

1.216

1.36 x 10 -4

2.724

1.246

2.73 x 10 -3

2.687

1.307

 

Table 3 Mean Absorbance Values for Bisphenol A and Associated Solvent Control Cultures in the Definitive Test

 

Nominal Concentration (mg/l)

Absorbance (540 nm)

 

 

Bisphenol A

Solvent Control

0.049

1.229

1.190

0.098

1.235

1.237

0.20

1.225

1.260

0.39

1.322

1.240

0.78

1.501

1.210

1.56

1.669

1.217

3.13

1.772

1.268

6.25

2.239

1.227

12.5

2.551

1.234

25

2.780

1.216

50

2.675

1.246

100

2.071

1.307

 

Table 4 - Mean Absorbance Values for the Test Material and Associated Solvent Control Cultures in the Definitive Test

 

 

Nominal Concentration (mg/l)

Absorbance (540 nm)

 

 

Test Material

Solvent Control

100

1.211

1.092

100

1.214

1.069

100

1.189

1.081

100

1.214

1.119

100

1.194

1.113

100

1.220

1.076

100

1.228

1.080

100

1.214

1.102

100

1.222

1.092

100

1.224

1.113

100

1.233

1.123

100

1.231

1.161

 

Care should be taken in the interpretation of these results as a negative result in thisin vitrostudy does not necessarily indicate that the test material will not have an effect in the environment.

 

Bisphenol A was determined to be 26 000 times less potent than17β-estradiol.

 

The decrease in absorbance value obtained for Bisphenol A at the highest two concentrations tested was considered to be due to toxicity and the associated inhibition of the P- galactosidase enzyme responsible for the metabolism of chlorophenol red P- D-galactopyranoside (CPRG) from its normal yellow colour to the red product that is monitored at 540 nm as a measure of oestrogenic activity.

 

The response of the recombinant yeast screen assay to both positive control materials was comparable to published results thereby confirming the suitability of the inoculum and culture conditions.


 

Applicant's summary and conclusion

Conclusions:
The test material showed no significant oestrogenic activity at the test concentration of 100 mg/l and Bisphenol A was determined to be 26 000 times less potent than 17β-estradiol.

Care should be taken in the interpretation of these results as a negative result in this in vitro test does not necessarily indicate that the test material will not have an effect in the environment.
Executive summary:

The test material showed no significant oestrogenic activity at the test concentration of 100 mg/l and Bisphenol A was determined to be 26 000 times less potent than 17β-estradiol.

 

Care should be taken in the interpretation of these results as a negative result in thisin vitrotest does not necessarily indicate that the test material will not have an effect in the environment.