2,2'-dihydroxy-4,4'-dimethoxybenzophenone

Short-term toxicity to aquatic invertebrates

Administrative data

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

information not available

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

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

Cross-reference

Reason / purpose for cross-reference:

read-across: supporting information

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

Information not available.

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

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

Guideline:

other: not specified

GLP compliance:

not specified

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: test material obtained from Sigma-Aldrich (St Louis, MO, USA)

Analytical monitoring:

not specified

Vehicle:

not specified

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: a stock solution was prepared in reconstituted water (ISO 1982)
- Controls: reconstituted ISO water

Test organisms (species):

other aquatic worm: Freshwater planarian D. japonica

Details on test organisms:

TEST ORGANISM
- Common name: Dugesia japonica
- Justification for species other than prescribed by test guideline: Freshwater free-living planarians are common aquatic invertebrates in both unpolluted rivers and lakes, and play an important role in aquatic ecosystem by acting as carnivores, omnivores, or detritivores. Freshwater planarians have been suggested as suitable
test organisms for various types of short-term toxicity bioassays. In particular, they are sensitive to different types of environmental pollutants and can be easily maintained in laboratory inexpensively. For example, freshwater planarians, Dugesia japonica, showed a similar sensitivity to acute toxicity of different surfactants compared with the most common invertebrate test species, Daphnia magna.
- Source: D. japonica, were collected from Nan-shi stream located in Wu-Lai (24 790 N, 121 520 E) of northern Taiwan. Since then, the animals have been maintained asexually in dechlorinated tap water at room temperature and were fed with raw chicken liver once a week.
- Feeding during test: No. The test animals were not fed at least 4 days before the start of the toxicity tests and during the whole test duration.

METHOD FOR PREPARATION AND COLLECTION OF EARLY INSTARS OR OTHER LIFE STAGES: The planarians used for the test had a body length of 0.7 ± 0.1 cm.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Test temperature:

25 ± 1 °C

Nominal and measured concentrations:

0.5 - 50 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: beakers
- Type (delete if not applicable): open
- Material, size, headspace, fill volume: 50mL of test solution in a glass beaker :
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 5
- No. of vessels per control (replicates): 5

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: reconstituted water (ISO 1982), including 2.5 mmol/L CaCl2, 0.4 mmol/L MgSO4, 0.8 mmol/L NaHCO3, and 77 mmol/L KCl.
- Culture medium different from test medium: Yes, dechlorinated tap water.

OTHER TEST CONDITIONS
- Photoperiod: 12 : 12 h dark/light cycle

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : The animals were inspected every 24 h for mortality during the entire 96 h experimental period. The organisms without detectable movement were considered dead and removed from test solution.

VEHICLE CONTROL PERFORMED: no

Reference substance (positive control):

not specified

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

2.1 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Remarks on result:

other: 95% confidence limits: 1.7 - 2.7 mg/L

Duration:

72 h

Dose descriptor:

LC50

Effect conc.:

2.1 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Remarks on result:

other: 95% confidence limits: 1.7 - 2.7 mg/L

Key result

Duration:

48 h

Dose descriptor:

LC50

Effect conc.:

14 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Remarks on result:

other: 95% confidence limits: 10.9 - 17.9 mg/L

Duration:

24 h

Dose descriptor:

LC50

Effect conc.:

35 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Reported statistics and error estimates:

The concentrations that were lethal to 50% of the organisms (LC50) at 24, 48, 72, or 96 h were calculated using trimmed Spearman–Karber analysis with trimmed
Spearman–Karber program (version 1.5) which were obtained from Environmental Monitoring Systems Laboratory (USEPA, Cincinnati, OH). The Pearson’s correlation coefficients were calculated to determine the relationship between acute toxicity of D. japonica and D. magna.

Validity criteria fulfilled:

not specified

Conclusions:

In a study with the aquatic invertebrate Dugesia japonica under static conditions, toxic effects of 2,2-Dihydroxy-4,4-dimethoxybenzophenone (Benzophenone-6) were investigated. The following results were determined for the compound: LC50 (24 h) = 35 mg/L, LC50 (48 h) = 14 mg/L, LC50 (72 h) = 2.1 mg/L, LC50 (96h) = 2.1 mg/L. The LC50 (48h) was regarded as key value, since the test duration of 48 h is recommended for acute toxicity testing on aquatic invertebrates according to relevant standard test guidelines.
Based on this result, the test item does not need to be classified as acute toxic to the aquatic environment. With regard to chronic toxicity, taking into account the facts that the test item is soluble in water, i.e. above the determined EC50 value, and not readily biodegradable, the test item should be classified as aquatic chronic Cat. 3.

Executive summary:

Within this study fourteen benzophenone-type UV filters and four paraben preservatives were selected to examine their acute toxicities on Dugesia japonica. The 48-h LC₅₀ values for planarians exposed to benzophenone-type UV filters can be ranked as oxybenzone >mexenone >5-chloro-2-hydroxybenzophenone >2,4- dihydroxybenzophenone >hydroxybenzophenone >dioxybenzone>benzophenone >2,2,4,4-Tetrahydroxybenzophenone >4-hydroxybenzophenone >3-hydroxybenzophenone >4,4-dihydroxybenzophenone >2,2-dihydroxy-4,4-Dimethoxybenzophenone >2,3,4-trihydroxybenzophenone >sulisobenzone with a range from 0.9 to 145 mg/L with a similar sequence for the 96 h LC₅₀ values, ranging from 0.5 to 77mg/L. Among all the tested chemicals, oxybenzone was the most toxic and sulisobenzone the least toxic chemical to planarian at each exposure period. Most benzophenone-type UV filters are toxic to aquatic animals with 48 h LC₅₀ values less than 10 mg/L, except for 2,2-dihydroxy-4,4-dimethoxybenzophenone, 2,3,4-trihydroxybenzophenone, and sulisobenzone.

The LC₅₀ (48h) for Dugesia japonica exposed to 2,2-Dihydroxy-4,4-dimethoxybenzophenone (Benzophenone-6, CAS 131-54-4) was determined to be 14 mg/L.

Data source

Reference

Reference Type:

publication

Title:

Acute Toxicity and Ecological Risk Assessment of Benzophenone and N,N-Diethyl-3 Methylbenzamide in Personal Care Products

Author:

Sun H-Q

Year:

2016

Bibliographic source:

International Journal of Environmental Research and Public Health - Open Access Journal (www.mdpi.com/journal/ijerph)

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

other: Chinese National Standards: GB/T 16125-2012 (daphnia magna straus)

Deviations:

yes

Remarks:

test duration of 24 h only

Test guideline 2

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Test guideline 3

Qualifier:

equivalent or similar to guideline

Guideline:

ISO 6341 (Water quality - Determination of the Inhibition of the Mobility of Daphnia magna Straus (Cladocera, Crustacea))

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

Benzophenone

EC Number:

204-337-6

EC Name:

Benzophenone

Cas Number:

119-61-9

Molecular formula:

C13H10O

IUPAC Name:

benzophenone

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: The test material was purchased from Sinopharm Chemical Reagent Co. Ltd. (Shanghai, China)

Sampling and analysis

Analytical monitoring:

no

Test solutions

Vehicle:

yes

Remarks:

dimethyl sulfoxide (cosolvent)

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: Aerated tap water was used to prepare a serial concentration of Benzophenone solution.
- Eluate:
- Differential loading:
- Controls: Aerated tap water
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): dimethyl sulfoxide (cosolvent)
- Concentration of vehicle in test medium (stock solution and final test solution(s) or suspension(s) including control(s)):
- Evidence of undissolved material (e.g. precipitate, surface film, etc.):

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna
- Strain/clone: Straus
- Source: obtained from the Freshwater Algae Culture Collection at the Institute of Hydrobiology, Chinese Academy of Sciences (Wuhan, China). The D. magna were cultured in the laboratory.

ACCLIMATION
not specified

METHOD FOR PREPARATION AND COLLECTION OF EARLY INSTARS OR OTHER LIFE STAGES:
The D. magna for the test were 6–24-h old.

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

24 h

Test conditions

Test temperature:

25 ± 2 °C

pH:

7.0 - 8.0

Nominal and measured concentrations:

The chemical concentrations of the definitive test were set up based on the results of the pre-test, so the concentration range is narrow and has good linear relation to the mortality rates. Five concentrations in the concentration range of 2.00 - 12.00 mg/L were tested.

Details on test conditions:

TEST SYSTEM
- Test vessel: beakers
- Type (delete if not applicable): open
- Material, size, headspace, fill volume: 100-mL glass beaker with 80 mL of solution
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 3
- No. of vessels per vehicle control (replicates): 3 (cosolvent)

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Aerated tap water

OTHER TEST CONDITIONS
- Photoperiod: 12 h:12 h light-dark cycle

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
The numbers of the dead individuals were recorded at the end of the test.

TEST CONCENTRATIONS
- Spacing factor for test concentrations: not specified
- Range finding study: A pre-test was conducted but no details were specified in the publication.
- Test concentrations: 2.00 - 12.00 mg/L
- Results used to determine the conditions for the definitive study: The chemical concentrations were set up based on the results of a pre-test, so the concentration range is narrow and has good linear relation to the mortality rates.

Reference substance (positive control):

yes

Remarks:

The D. magna were cultured in the laboratory and were tested by potassium dichromate before the toxicity experiments.

Results and discussion

Effect concentrations

Key result

Duration:

24 h

Dose descriptor:

LC50

Effect conc.:

7.63 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Remarks on result:

other: 95% confidence intervall: 7.13 - 8.14 mg/L

Reported statistics and error estimates:

IBM SPSS version 20 software (IBM, Armonk, NY, USA) was applied to calculate the 24-h median lethal concentration (LC50) of D. magna.

Any other information on results incl. tables

Results

There was no significant difference between the dimethyl sulfoxide control group at the highest concentration and the blank control group for D. magna lethal rate by analysis of variance. This indicated that dimethyl sulfoxide had no repression effect on D. magna in this study. All the results were analyzed by comparing the testing to the blank control groups.

Acute Toxicity of Benzophenone to Daphnia magna

When the concentrations range from 2.00 to 12.00 mg/L, the relationship between the mortality of D. magna and Benzophenone concentration was described by a linear equation:

y = -10.802 + 7.989x, (x : 2.00 mg/L - 12.00 mg/L)

where x is the Benzophenone concentration, and y is the mortality of D. magna (%).

The 24-h LC50 of D. magna for Benzophenone was 7.63 mg/L (95% confidence interval: 7.13–8.14 mg/L)

Applicant's summary and conclusion

Validity criteria fulfilled:

not specified

Conclusions:

The study was performed according to Chinese National Standards (GB/T 16125-2012 (daphnia magna straus)) on Benzophenone without obvious deviations which may have impact on the validity of the study. Thus, the results were obtained via a scientifically reasonable method. Hence, there is no doubt that the obtained results are not reliable.
Under the conditions of the test, there was a significant mortality of daphnias at concentrations >2.00 mg/L. The following LC-value was determined accordingly after 24 hours: LC50 = 7.63 mg/L.

Executive summary:

In the present 24 h acute toxicity sudy according to Chinese National Standards, the toxic effect of Benzophenone and N,N-diethyl-3-methylbenzamide on Chlorella vulgaris, Daphnia magna, and Brachydanio rerio was tested and the ecotoxicological risks were evaluated.

For Benzophenone the 24-h median lethal concentration (LC₅₀) on Daphnia magna was 7.63 mg/L.