4,4'-isopropylidenediphenol

Toxicity to microorganisms

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

toxicity to microorganisms, other

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Neither the results nor the methods were clearly presented or explained. Concentrations greater than 320 mg/L could not be tested.

Qualifier:

equivalent or similar to guideline

Guideline:

DIN 38412-8 (Pseudomonas Zellvermehrungshemmtest)

Deviations:

not specified

GLP compliance:

yes

Analytical monitoring:

yes

Vehicle:

yes

Test organisms (species):

Pseudomonas putida

Test type:

static

Water media type:

not specified

Limit test:

no

Total exposure duration:

18 h

Details on test conditions:

Type: other: liquid broth cultures

Reference substance (positive control):

no

Key result

Duration:

18 h

Dose descriptor:

EC10

Effect conc.:

> 320 mg/L

Nominal Test Concentrations: 0.23, 0.46, 0.93, 1.87, 3.75, 7.50, 15.00, 30.00, 60.00, 120.00, 240.00, 320.00 mg/L. The inhibition concentration was >320 mg C/L. Higher concentrations appeared to stimulate bacterial growth indicating it was an energy source. Bisphenol A had a low solubility and as a result an exact inhibitory concentration could not be determined. Researchers attempted to increase BPA concentrations by dissolving the compound in dimethyl formamide but it precipitated out again when the BPA solution was mixed with the culture medium preventing a turbidimetric determination from being made.

Validity criteria fulfilled:

not specified

Conclusions:

The biodegradability of Bisphenol A in liquid broth culture to Pseudomonas putida was studied. In this study, an EC10 of >320 mg/L was reported. While this study is not the same as the activated sludge respiration test that would typically be performed to satisfy this data need, Bisphenol A is readily biodegradable and does not show high toxicity to microbial populations. The Weight of Evidence suggests that no additional studies are necessary for the assessment of microbial populations exposed to Bisphenol A.

Executive summary:

The biodegradability of Bisphenol A in liquid broth culture to Pseudomonas putida was studied. In this study, an EC10 of >320 mg/L was reported. While this study is not the same as the activated sludge respiration test that would typically be performed to satisfy this data need, Bisphenol A is readily biodegradable and does not show high toxicity to microbial populations. The Weight of Evidence suggests that no additional studies are necessary for the assessment of microbial populations exposed to Bisphenol A.

Reference 2

Endpoint:

toxicity to microorganisms, other

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Study method details are lacking.

Principles of method if other than guideline:

Method: 79/931/EEC, Annex V of the 6th Amendment

GLP compliance:

not specified

Analytical monitoring:

not specified

Vehicle:

not specified

Test organisms (species):

Pseudomonas fluorescens

Test type:

not specified

Water media type:

not specified

Limit test:

no

Total exposure duration:

16 h

Details on test conditions:

Type: aquatic

Reference substance (positive control):

not specified

Key result

Duration:

16 h

Dose descriptor:

IC50

Effect conc.:

54.5 mg/L

Nominal / measured:

not specified

Conc. based on:

not specified

Basis for effect:

growth inhibition

The IC50 of the control was 7 mg/L. The IC50 for inhibition with BPA was 54.5 mg/L.

Validity criteria fulfilled:

not specified

Conclusions:

The biodegradability of Bisphenol A was studied in a number of tests. One of them evaluated the inhibition of growth of the bacteria, Pseudomonas fluorescens. In this microbial inhibition test, the IC50 for the inhibition of growth of Pseudomonas by Bisphenol A was 54.5 mg/L.

Executive summary:

The biodegradability of Bisphenol A was studied in a number of tests. One of them evaluated the inhibition of growth of the bacteria, Pseudomonas fluorescens. In this microbial inhibition test, the IC50 for the inhibition of growth of Pseudomonas by Bisphenol A was 54.5 mg/L. While this study is not the same as the activated sludge respiration test that would typically be performed to satisfy this data need, Bisphenol A is readily biodegradable and does not show high toxicity to microbial populations. The Weight of Evidence suggests that no additional studies are necessary for the assessment of microbial populations exposed to Bisphenol A.

Description of key information

Two studies are available which were rated with Klimisch 2 (reliable, with restrictions) were used in a weight-of-evidence (WoE) approach to derive PNEC STP. Fabig (1988) reported an 18 h-EC10 of > 320 mg/L (highest test concentration) with Pseudomonas putida. This study is not the same as an activated sludge respiration test according to OECD 209 but there is indication of no toxicity towards P. putida as a microorganism.

Stone and Watkinson (1983) as well is not an OECD 209 study but investigated biodegradation with a bacteria growth inhibition test with Pseudomonas fluorescens. The IC50 was reported as 54.4 mg/L.

Both studies were used in a WoE approach. The REACH guidance document R.10 specifies that studies with P. fluorescens are of limited relevance for STP as this species uses glucose as substrate. However, a growth inhibition test with P. putida may be used for PNEC STP derivation. The study of Fabig (1988) was conducted in accordance with DIN 38412-8 while the recent REACH guidance document R.10 asks for ISO-10712 (1996). Despite the fact that it is not totally certain if the DIN translated directly into the ISO the study is considered sufficiently reliable to be used in a WoE approach. Thus, the EC10 > 320 mg/L was used for PNEC derivation. This approach was also taken in the European Risk Assessment report (2010).

Key value for chemical safety assessment

EC10 or NOEC for microorganisms:

320 mg/L