Benzoyl chloride, 3-methoxy-2-methyl-

Short-term toxicity to fish

Administrative data

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Study period:

17 February 1997 - 21 February 1997

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study conducted to GLP in compliance with agreed protocols, with no or minor deviations from standard test guidelines and/or minor methodological deficiencies, which do not affect the quality of the relevant results.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1997

Report date:

1997

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method C.1 (Acute Toxicity for Fish)

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

-

EC Number:

427-440-1

EC Name:

-

Cas Number:

24487-91-0

Molecular formula:

C9H9ClO2

IUPAC Name:

2-Methyl-3-methoxy benzoyl chloride

Test material form:

other: solid

Details on test material:

MMBC
Appearance: Light brown solid
Storage conditions: In darkness at room temperature

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
The test substance rapidly hydrolysed to MMBA.

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

TEST SUBSTANCE PREPARATION
The test substance was added to diluent water to give an initial stock solution of 199.2 mg test substance equivalents/L and ultrasonicated for approximately 90 minutes so that test substance dissolved by hydrolysis to MMBA. The pH of this stock solution was then adjusted using 5.5 mL 1N sodium hydroxide to a pH of 7.8.
Serial dilutions of this stock solution were prepared with test water to give the desired series of exposure levels.

STABILITY OF TEST CONCENTRATIONS
Test concentrations were verified by chemical analysis. Duplicate medium samples (10 mL) were taken from the control and each exposure level at 0 hours (fresh media), 24 and 96 hours (expired media) and analysed.

CONCENTRATIONS
Five test concentrations were prepared plus one control.

Test substance rapidly hydrolysed
to MMBA with a half life of <15 minutes at 25°C in water. Based on this data, the compound in this study was initially converted to the hydrolysis product MMBA in order to test the compound up to a concentration of 100 mg/L as required in the pertinent guidelines. The method of analysis investigated the concentration of MMBA, however all results are expressed as mean measured concentration of MMBC equivalents. Measured concentrations ranged from 100 to 110% of nominal at 0 hours, 101 to 108% of nominal at 24 hours, and 105 to 112% of nominal at 96 hours.

Test solutions

Vehicle:

no

Test organisms

Test organisms (species):

Oncorhynchus mykiss (previous name: Salmo gairdneri)

Details on test organisms:

TEST ORGANISM
- Common name: Rainbow trout
- Source: Westacre Trout Farm, Norfolk, UK.
- Age at study initiation (mean and range, SD): Not reported.
- Length at study initiation (length definition, mean, range and SD): The control fish were measured at the end of the exposure period. Mean standard length was found to be 3.2 cm (SD = 0.32).
- Weight at study initiation (mean and range, SD): The control fish were measured at the end of the exposure period. Mean weight was determined as 0.86 g (SD = 0.14).
- Feeding during test: No

ACCLIMATION
- Acclimation period: 13 days.
- Acclimation conditions (same as test or not): Temperature remained within the range 14 to 15 °C and dissolved oxygen within the range 9.5 to 10.1 mgO2/L.
- Type and amount of food: Commercial fry pellet, fed to repletion. No food was given during the 24 hour period immediately prior to exposure.
- Feeding frequency: Daily
- Health during acclimation (any mortality observed): No medication was given during the acclimatisation period and mortalities were recorded as <1% in the 7 days prior to the test.

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Test conditions

Hardness:

136 - 181 mg CaCO3/L, calculated daily.

Test temperature:

13 ± 1 °C

pH:

7.6 - 8.1

Dissolved oxygen:

9.1 - 10.2

Nominal and measured concentrations:

Nominal test concentrations: 4.58, 9.96, 21.9, 45.8 and 99.6 mg test substance equivalents/L.
Mean measured test concentrations: 5.06, 10.8, 23.5, 46,8 and 103 mg test substance equivalents/L.

Details on test conditions:

TEST SYSTEM
- Test vessel: Glass aquaria containing prepared test medium or diluent water.
- Material, size, headspace, fill volume: Each vessel contained 20 litres of medium to a depth of 19 cm (approximate dimensions of vessel: 25 x 46 x 25 cm).
- Aeration: Supplementary aeration was provided via a narrow bore glass.
- No. of organisms per vessel: 10
- Biomass loading rate: 0.43 g bodyweight/litre (static volume).

DILUENT WATER
The water used for the study was laboratory tap water filtered, dechlorinated and softened by passage through an Elga water purification system. The water passed in sequence through a high pressure sand filter to remove colloids and particulate matter and a high grade activated carbon filter to remove chlorine and any organic contaminants. A proportion of the supply then passed through a water softener before final reverse osmosis treatment to produce a highly purified water supply. The two grades of dechlorinated water were then remixed in the ratio of approximately 1 : 1 to give a supply with the desired water hardness.

Chlorine levels ranged from 0.00 to 0.09 mg/L in the seven days of the acclimatisation period and the mean hardness level, calculated from daily measurements during the same period, was between 136 and 181 mg CaCO3/L.
The water was analysed and the levels of dissolved minerals, metals and organics was found to be not significant.

OTHER TEST CONDITIONS
- Photoperiod: 16 hours light, 8 hours darkness.

CRITERIA OF EFFECT
The criteria of death employed were (i) absence of respiratory movement and (ii) absence of response to physical stimulation of the caudal peduncle.

In addition to observations on mortality at 3, 6, 24, 48, 72 and 96 hours, subjective assessments were also made on the type and incidence of sub-lethal effects compared with control fish.

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 103 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

other: MMBC equivalents as the test material hydrolyses rapidly to MMBA

Basis for effect:

mortality (fish)

Effect concentrations 2

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

> 103 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

other: MMBC equivalents as the test material hydrolyses rapidly to MMBA

Basis for effect:

mortality (fish)

Details on results:

There were no mortalities observed in any of the test levels.
In addition, no sub-lethal effects were observed in any of the fish at any concentration.

Any other information on results incl. tables

Sublethal observations / clinical signs:

Table 1 Summary of Chemical Analysis Results

Nominal Concentration (mg/L)	Measured Concentration			QC Samples % Recovery
	As MMBA (mg/L)	As MMBC (mg/L)	As a % of Nominal
0 hours Control 4.6 10 22 46 100	ND 4.518 9.558 20.95 41.03 92.30	- 5.042 10.67 23.37 45.78 103.0	- 110 107 106 99.5 103	- 99.7   98.3   90.4
24 hours Control 4.6 10 22 46 100	ND 4.471 9.594 20.63 41.58 90.96	- 4.989 10.71 23.02 46.40 101.5	- 108 107 105 101 102	- 99.1   99.6   89.8
96 hours Control 4.6 10 22 46 100	ND 4.616 9.933 21.55 43.17 94.47	- 5.151 11.08 24.04 48.17 105.4	- 112 111 109 105 105	- 103   102   93.0

ND = None Detected

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The 96 h LC50 value for the test substance with rainbow trout was >103 mg test substance equivalents/L.

Executive summary:

The acute toxicity of the test substance to fish was investigated in Oncorhynchus mykiss (rainbow trout) in accordance with standardised guidelines OECD 203 and EU Method C.1. Groups of ten fish were exposed to hydrolysed test substance for 96 hours at nominal concentrations of 4.58, 9.96, 21.9, 45.8 and 99.6 mg test substance equivalents/L dissolved in water (mean measured concentrations of 5.06, 10.8, 23.5, 46.8 and 103 mg test substance equivalents/L). Since the test substance was seen to convert to the hydrolysis product MMBA, the method of analysis investigated the concentration of MMBA, however, all the results were expressed as mean measured concentration of test substance equivalents. During the study, observations were made on the numbers of dead fish and the incidence of sub-lethal effects after 3, 6, 24, 48, 72 and 96 hours exposure. No mortalities or sub-lethal effects were observed, therefore the 96 hour LC50 value was estimated to be greater than 104 mg test substance equivalents/L.