Benzoyl chloride

Short-term toxicity to aquatic invertebrates

Administrative data

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

no data

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

The study was performed according to the EPA 660/3-75-009 guideline which is similar to the EPA OPPTS 850.1045 (Penaeid Acute Toxicity Test). No data on the GLP procedure was reported but validity criteria were partially fulfilled. Thus we consider this study to be a Klimisch 2e study since it is well documented, meets generally accepted scientific principles and is acceptable for assessment.

Data source

Reference

Reference Type:

publication

Title:

Acute toxicity of 12 industrial chemicals to freshwater and saltwater organisms

Author:

Curtis M.W., Copeland T.L. and Ward C.H.

Year:

1979

Bibliographic source:

Water research, 13: 137-141

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

other: EPA 660/3-75-009 (Methods for Acute Toxicity Tests with Fish, Macroinvertebrates and Amphibians)

Deviations:

not specified

Test guideline 2

Qualifier:

equivalent or similar to guideline

Guideline:

EPA OPPTS 850.1045 (Penaeid Acute Toxicity Test)

Deviations:

yes

Remarks:

no range finding test was performed and the test was static with Palaemonetes pugio as test species

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

Benzoyl chloride

EC Number:

202-710-8

EC Name:

Benzoyl chloride

Cas Number:

98-88-4

Molecular formula:

C7H5ClO

IUPAC Name:

benzoyl chloride

Details on test material:

- Name of test material (as cited in study report): benzoyl chloride
- Stability under test conditions: Benzoyl chloride reacted with water to give benzoic acid and HCl

No more data available

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

- Sampling method: 100 mL water samples were taken from one tank at each concentration at the beginning and the end of the test to quantify the toxicant concentration at these time points.

No more data available

Test solutions

Vehicle:

not specified

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: test substance was either administered directly or in the form of a stock solution in deionized water or aceton
- Controls: at least two control aquaria with additional control aquaria for any solvents used to introduce the test substance into the test solution
- Other: after adding the test substance the test solution was briefly stirred with a glass rod

No more data available

Test organisms

Test organisms (species):

Palaemonetes pugio

Details on test organisms:

TEST ORGANISM
- Common name: grass shrimp
- Source: Galveston Bay system


ACCLIMATION
- Acclimation period: minimal acclimation procedure necessary since the shrimp were held for a minimum of 10 days under the testing conditions
- Acclimation conditions: same as test
- Type and amount of food: cereal-type pellets supplied by Texas A & M
- Feeding frequency: organisms were not fed in the 48h prior to the test to prevent fouling of test aquaria
- Other: temperature in holding tanks was monitered for 48h prior to the test to detect any gross fluctuations from 22°C

Study design

Test type:

static

Water media type:

saltwater

Limit test:

no

Total exposure duration:

96 h

Post exposure observation period:

no data

Test conditions

Hardness:

no data

Test temperature:

22 +-/ 1°C

pH:

At the start of the test 8.3 - 8.7
At the end of the test 7.2

Dissolved oxygen:

The dilution water was intensely aerated prior to use in the test.
During the 96h test period dissolved oxygen was determined in each aquaria every 24h. For the controls the dissolved oxygen ranged between 6.5 and 7.2 mg/L. A detailed overview of all the dissolved oxygen measurements for the tested nominal benzyol chloride concentrations are given in Table 1 in other information on materials and methods.

Salinity:

25 +-/ 1 ppt

Nominal and measured concentrations:

Nominal concentrations: 18.0, 30.0, 50.0, 83.0, 139.0, 233.0 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Type (delete if not applicable): open
- Material, size, headspace, fill volume: five gallon distilled water bottles with the necks removed; fill volume of 12 L (depth of approximately 24 cm)
- No. of organisms per vessel: 5 organisms
- No. of vessels per concentration (replicates): 2
- No. of vessels per control (replicates): 3
- Biomass loading rate: <0.8 g/L


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: 25 ppt Instant Ocean synthetic water (Aquarium Systems, Inc. Easklake, Ohio)
- Intervals of water quality measurement:
every 24h dissolved oxygen and temperature were determined in each aquaria
at the end of the test pH was measured


OTHER TEST CONDITIONS
- Photoperiod: 16h light - 8h dark diurnal cycle


EFFECT PARAMETERS MEASURED (with observation intervals if applicable):
- during the 96h of exposure deaths were recorded
- every 24h percentage of survival was determined


TEST CONCENTRATIONS
- Spacing factor for test concentrations: test concentrations were arranged in geometric series with a dilution factor of at least 60%

No more data available

Reference substance (positive control):

not specified

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

180 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Remarks on result:

other: 99.8% CI (due to lack of partial kills): 139.0 - 233.0 mg/L

Effect concentrations 2

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

0.12 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

mortality

Details on results:

- At 24h and 48h no mortality was observed thus no LC50 and 95% confidence interval are reported. A detailed overview of the % mortality for all nominal concentrations at the different time points is given in table 2 in remarks on tables and figures.

- Mortality of control: 0% mortality for the controls at 24h, 48h and 72h. At time point 96h a mortality of 7% was observed (table 2).

- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values:
Benzoyl chloride reacted with water to give benzoic acid and HCl (see recovery efficiency details in free text)

No more data available

Results with reference substance (positive control):

no data

Reported statistics and error estimates:

- LC50's and confidence intervals were determined by either probit analysis, moving average method or the binomial test depending on the number of partial kills observed.
Specific statistics methods for the benzoyl chloride are unknown.
- A linear regression analysis was performed to compare the measured concentrations to the nominal concentration of the test substance. A correlation coefficient greater than 0.90 implies a linear relationship between the measured and nominal concentrations. Results of this analysis are given in the remarks section.

- Additional LC50's were computed on the basis of measured concentrations when the correlation coefficient was greater than 0.90 (arbitrary limit)

Any other information on results incl. tables

- Table 2: % mortality determined every 24h for control and nominal test concentrations during the 96h test period

Nominal benzoyl chloride concentration (mg/L)	Mortality (%)
	24h	48h	72h	96h
Control	0	0	0	7
18.0	0	0	0	0
30.0	0	0	0	0
50.0	0	0	0	0
83.0	0	0	0	0
139.0	0	0	0	0
233.0	0	0	60	100

- Recovery efficiencies:

Analytical monitoring showed that the mean % recovery for benzoyl chloride is 103.3% with a standard deviation of 15.7%. The mean % recovery consists of an average of 94% recovery as benzoic acid and 9% as benzoyl chloride.

- Results from the linear regression analysis between the nominal and measured benzoyl chloride concentrations:

A correlation of 0.97 was observed between the nominal and measured concentrations. The slope was 0.0007

Applicant's summary and conclusion

Validity criteria fulfilled:

no

Remarks:

partially fulfilled

Conclusions:

The authors tested the toxicity of benzoyl chloride to the shrimp Palaemonetes pugio according to guideline EPA 660/3-75-009 which is similar to EPA OPPTS 850.1045. The LC50(96h) was estimated to be equal to 180 mg/L (nominal concentration) and therefore, at this level of information benzoyl chloride can not be classified based on the classification categories given in the CLP regulation (EC) No 1272/2008 as for crustaceans the EC50 after 48h is requested.
The study also revealed that benzoyl chloride reacts with the dilution water forming benzoic acid and HCl. The latter causes a decrease in pH while the biological oxygen demand of the former is believed to be the major cause of the 100% mortality at 96h at a nominal concentration of benzoyl chloride of 233 mg/L since dissolved oxygen levels deminished to 0.6 mg/L for this time point.

Executive summary:

In a short-term toxity study according to guideline EPA 660/3-75-009 which is similar to EPA OPPTS 850.1045, white shrimps from the species Palaemonetes pugio were exposed under static conditions to benzoyl chloride during 96h in salt water. Two series of five organisms were exposed to a range of nominal concentrations (i.e. 18.0, 30.0, 50.0, 83.0, 139.0, 233.0 mg/L) and three controls were included. The percentage of mortality was monitored and LC 50 (96h) and confidence intervals were determined by either probit analysis, moving average method or the binomial test depending on the number of partial kills observed.

The percentage of mortality in the controls during the 96h test period was below 10%. The LC50(96h) was calculated to be 180 mg/L (99.8% CI: 139.0 - 233.0 mg/L) based on nominal concentrations and 0.12 mg/L based on measured concentrations. Hence, at this level of information, benzoyl chloride can not be classified based on the classification categories given in the CLP regulation (EC) No 1272/2008 since the EC50 after 48h is requested for crustacea.

The quick degradation of benzoylchloride into benzoic acid and HCl in the dilution water resulted in a drop in pH to 7.2 caused by HCl and more importantly benzoic acid depleted the dissolved oxygen which most likely caused the 100% mortality after 96h at a nominal concentration of 233.0 mg/L benzoylchloride (dissolved oxygen measured was 0.6 mg/L).

No data on the GLP procedure was reported and validity criteria were partially fulfilled. The mortality in the controls should not have exceeded 10% during the 96h testing period. Thus, this validity criteria was met as only 7% mortality was observed at 96h. Furthermore the dissolved oxygen levels should be above 60% of saturation. This criteria was not fulfilled as the biological oxygen demand of benzoic acid (degradation product of benzoyl chloride) caused a drop in dissolved oxygen at multiple time points and nominal concentrations of benzoyl chloride resulting in a saturation level below 60%. However, this parameter is an intrinsic property of the substance in water and quantification of the degradation products was succesfull. Altogether, considering these elements and the level of details of the investigation, the study should be considered as reliable with restrictions, a Klimisch 2.e study.