(2-methoxyethyl)benzene

Acute Toxicity: dermal

Administrative data

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

Data is from study report.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2019

Report date:

2019

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Principles of method if other than guideline:

The objective of this acute dermal toxicity study was to assess the toxicological profile of the test item on application as a single semi-occlusive dermal application to rats.

GLP compliance:

yes

Test type:

fixed dose procedure

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

(2-methoxyethyl)benzene

EC Number:

222-619-7

EC Name:

(2-methoxyethyl)benzene

Cas Number:

3558-60-9

Molecular formula:

C9-H12-O

IUPAC Name:

(2-methoxyethyl)benzene

Test material form:

liquid

Details on test material:

- Name of test material: Benzene(-2-methoxyethyl)
- Molecular formula: C9H12O
- Molecular weight: 136.193 g/mole
- Smiles : COCCc1ccccc1
- Inchl: InChI=1/C9H12O/c1-10-8-7-9-5-3-2-4-6-9/h2-6H,7-8H2,1H3
- Substance type: Organic
- Physical state: Liquid

Specific details on test material used for the study:

- Name of test material: Benzene(-2-methoxyethyl)
- Molecular formula: C9H12O
- Molecular weight: 136.193 g/mole
- Smiles : COCCc1ccccc1
- Inchl: InChI=1/C9H12O/c1-10-8-7-9-5-3-2-4-6-9/h2-6H,7-8H2,1H3
- Substance type: Organic
- Physical state: Clear colourless, mobile liquid, almost insoluble in water
- Purity as per Certificate of Analysis: 99.7302%
- Lot No. : PE0201/18
- Manufactured date : Jan 2018
- Expiry Date : Dec 2022
- pH :6.81
- Density :0.952g/cm3
- Storage conditions : Ambient (+18 to +36ºC)

Test animals

Species:

rat

Strain:

Wistar

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: In-vivo Biosciences,Bengaluru,Karnataka, India
- Females (if applicable) nulliparous and non-pregnant: yes
- Age at study initiation: 9 to 11 weeks
- Weight at study initiation: Females:226.2 to 233.5 g
- Identification:By rat accession number. Identification of individual rats is by cage card and crystal violet and turmeric body markings. The temporary body marking during acclimatization period was done with crystal violet. The rat accession numbers were allotted during the course of the study and was included in raw data and reported.
- Housing: Animals were housed individually in standard polysulfone cages (Size: approximately L 425 x B 266 x H 185 mm), with stainless steel top grill having facilities for pelleted food and drinking water in polycarbonate bottle.Additionally, polycarbonate rat huts were placed inside the cage as enrichment objects and were changed along with the cage once a week. Bedding: Steam sterilized corn cob was used and changed once a week along with the cage.
- Diet (e.g. ad libitum):Rat & Mice pellet feed, ad libitum
- Water (e.g. ad libitum): Deep bore-well water passed through activated charcoal filter and exposed to UV rays in Aquaguard on-line water filter-cum-purifier, ad libitum
- Acclimation period: the rats were acclimatized for six to fourteen days before treatment for dose range finding and main study respectively under standard laboratory conditions.

ENVIRONMENTAL CONDITIONS
- Temperature (°C):20 to 25°C
- Humidity (%): 64 to 68%
- Air changes (per hr): Air conditioned with adequate fresh air supply (13.3 to 14.1 air changes/hour).
- Photoperiod (hrs dark / hrs light): 12 hours light and 12 hours dark cycle

IN-LIFE DATES: From:05 December 2018 To: 02 January 2019

Administration / exposure

Type of coverage:

semiocclusive

Vehicle:

unchanged (no vehicle)

Details on dermal exposure:

TEST SITE
- Area of exposure: clipped skin of dorsolateral thoracic surface of the skin was clipped (approximately 10 x 8 cm) with an electric clipper (Aesculap - Germany).
- % coverage: 10% of the body surface
- Type of wrap if used: The applied area was covered with cotton gauze (size: Females: 8 x 5 cm of 6 ply) and it was secured in position by adhesive tape wound around the torso.

REMOVAL OF TEST SUBSTANCE
- Washing (if done): The dressing was removed and the applied area was washed with deionized water and wiped dry using clean towel.
- Time after start of exposure:24 hours

Duration of exposure:

24 hours

Doses:

DRF G1 - 200 mg/kg
DRF G2 - 1000 mg/kg
DRF G3 - 2000 mg/kg
Main G3 - 2000 mg/kg

No. of animals per sex per dose:

DRF G1 - 200 mg/kg - 1
DRF G2 - 1000 mg/kg - 1
DRF G3 - 2000 mg/kg - 1
Main G3 - 2000 mg/kg - 2

Control animals:

not specified

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing:
- Clinical examination and pre-terminal deaths:The animals were observed for clinical signs and pre-terminal deaths (mortality) once during first 30 minutes after application, and at hourly
intervals for 6 hours after application on the day of treatment (day 1) and once daily during Days 2 to 15. In addition, the site of applied area was observed for skin reactions at 24, 48
and 72 hours after removal of test chemical using the Draize criteria.All rats were observed for changes in skin and fur, eyes and mucous membranes, and also respiratory, circulatory, autonomic and central nervous systems and somatomotor activity and behaviour pattern. Attention was directed to observations of tremors, convulsions, salivation, diarrhoea, lethargy, sleep and coma.
- Body weights -Individual body weights of animals were recorded on test days 1 (Pre-application), 8 (7 days post application), and 15 (14 days post application).
- Necropsy of survivors performed: yes,at the end of the observation period, all rats were euthanised and exsanguinated under isoflurane anesthesia and subjected to detailed necropsy by an experienced prosector and the findings were recorded.
- Other examinations performed: Microscopic examination was not carried out as no gross pathological changes were observed.

Statistics:

not specified

Results and discussion

Preliminary study:

There was no information available on the toxicity of the test item. Hence, a starting dose of 200 mg/kg body weight was selected and tested in 1 female rat (dose range finding study). As there was no mortality at this dose range finding study as per Annexure 1 of the guideline the dose range finding study was continued with 1 female rat (dose range finding study) at the next higher dose of 1000 mg/kg body weight. There was no mortality, the dose range finding study was continued with 1 female rat (dose range finding study) at the next higher dose of 2000 mg/kg body weight. There was no mortality; the test was continued with the main study with 2 animals at the dose of 2000 mg/kg body weight to confirm the classification. There was no test item-related mortality.The subsequent dosing was done 2 to 3 days after the previous dosing.

Effect levels

Key result

Sex:

female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Remarks on result:

other: No mortality was observed

Mortality:

There were no pre-terminal deaths (mortality) observed during the study.

Clinical signs:

other: There were no clinical signs observed during the study. There were no skin reactions at the site of application at 24,48 and 72 hours after test patch removal (as per draize method).

Gross pathology:

No abnormality was detected at necropsy.

Other findings:

not specified

Any other information on results incl. tables

Table 1. Individual body weight, body weight changes and pre-terminal deaths

Group and Dose (mg/kg body weight)	Rat No.	Sex	Body weight (g)					Pre-terminal Initial deaths
			Initial (Day 1 - at treatment)	8thday	Weight change (day 8 – Initial)	15thday	Weight change (day 15 – Initial)
G1 and 200 DRF	Rw2363	F	229.0	236.3	7.3	248.6	19.6	0
G2 and 1000 DRF	Rw2364	F	233.5	239.8	6.3	248.9	15.4	0
G3 and 2000 DRF	Rw2365	F	226.2	238.6	12.4	247.6	21.4	0
G3 and 2000 Main study	Rw2366	F	226.2	239.5	13.3	250.7	24.5	0
	Rw2367	F	232.1	244.4	12.3	252.3	20.5	0

 

DRF: Dose Range Finding F: Female

 

Table 2: Individual test item application, clinical signs, skin reaction and necropsy findings 

Dose range finding study

 

Group & Dose (mg/kg body weight)

Date and time of application

Rat Number

Sex

Initial Bwt (g)

Volume (mL) applied

Observations and skin reaction

Days

1

2

3

4

5

30 min

1 h

2 h

3 h

4 h

5 h

6 h

*

Er @

Ed @

*

Er @

Ed @

*

Er @

Ed @

G1 and 200 DRF

11 December 2018 and 10:41 AM

Rw2363

F

229.0

0.05

N

N

N

N

N

N

N

N

N

0

0

N

0

0

N

0

0

 

 

Group & Dose (mg/kg body weight)

Rat Number

Sex

Observation

Necropsy findings

Days

6

7

8

9

10

11

12

13

14

15

G1 and 200 DRF

Rw2363

F

N

N

N

N

N

N

N

N

N

N

NAD

F: Female  N: Normal  h: hour   min: minutes   NAD: No abnormality detected   Er: Erythema   Ed: Edema

Score 0: No Erythema / Edema

 

Table 2 contd.: Individual test item application, clinical signs, skin reaction and necropsy findings

 

Group & Dose (mg/kg body weight)

Date and time of application

Rat Number

Sex

Initial Bwt (g)

Volume (mL) applied

Observations and skin reaction

Days

1

2

3

4

5

30 min

1 h

2 h

3 h

4 h

5 h

6 h

*

Er @

Ed @

*

Er @

Ed @

*

Er @

Ed @

G2 and 1000 DRF

14 December 2018 and 10:40 AM

Rw2364

F

233.5

0.25

N

N

N

N

N

N

N

N

N

0

0

N

0

0

N

0

0

 

Group & Dose (mg/kg body weight)

Rat Number

Sex

Observation

Necropsy findings

Days

6

7

8

9

10

11

12

13

14

15

G2 and 1000 DRF

Rw2364

F

N

N

N

N

N

N

N

N

N

N

NAD

F: Female  N: Normal  h: hour   min: minutes   NAD: No abnormality detected   Er: Erythema   Ed: Edema

Score 0: No Erythema / Edema

 

Table 2 contd.: Individual test item application, clinical signs, skin reaction and necropsy findings

Group & Dose (mg/kg body weight)

Date and time of application

Rat Number

Sex

Initial Bwt (g)

Volume (mL) applied

Observations and skin reaction

Days

1

2

3

4

5

30 min

1 h

2 h

3 h

4 h

5 h

6 h

*

Er @

Ed @

*

Er @

Ed @

*

Er @

Ed @

G3 and 2000 DRF

17 December 2018 and 11:10 AM

Rw2365

F

226.2

0.48

N

N

N

N

N

N

N

N

N

0

0

N

0

0

N

0

0

 

 

Group & Dose (mg/kg body weight)

Rat Number

Sex

Observation

Necropsy findings

Days

6

7

8

9

10

11

12

13

14

15

G3 and 2000 DRF

Rw2365

F

N

N

N

N

N

N

N

N

N

N

NAD

 

F: Female  N: Normal  h: hour   min: minutes   NAD: No abnormality detected   Er: Erythema   Ed: Edema

Score 0: No Erythema / Edema

 

Table 2 contd. Individual test item application, clinical signs, skin reaction and necropsy findings

 

Main study

Group & Dose (mg/kg body weight)

Date and time of application

Rat Number

Sex

Initial Bwt (g)

Volume (mL) applied

Observations and skin reaction

Days

1

2

3

4

5

30 min

1 h

2 h

3 h

4 h

5 h

6 h

*

Er @

Ed @

*

Er @

Ed @

*

Er @

Ed @

G3 and 2000 (Main)

19 December 2018 and 11:13 to 11:

Rw2366

F

226.2

0.48

N

N

N

N

N

N

N

N

N

0

0

N

0

0

N

0

0

Rw2367

F

232.1

0.49

N

N

N

N

N

N

N

N

N

0

0

N

0

0

N

0

0

 

 

Group & Dose (mg/kg body weight)

Rat Number

Sex

Observation

Necropsy findings

Days

6

7

8

9

10

11

12

13

14

15

G3 and 2000 (Main)

Rw2366

F

N

N

N

N

N

N

N

N

N

N

NAD

Rw2367

F

N

N

N

N

N

N

N

N

N

N

NAD

F: Female N: Normal h: hour min: minutes NAD: No abnormality detected Er: Erythema Ed: Edema

Score 0: No Erythema / Edema

*: Clinical signs; @: Skin scoring as per Draize method (approximately 24, 48 and 72 hours) after test patch removal

Applicant's summary and conclusion

Interpretation of results:

other: Not classified

Conclusions:

Based on the present study results, the acute dermal LD50 value of the given test chemical is >2000 mg/kg body weight in female Wistar rats.

Executive summary:

The acute dermal toxicity study was conducted by using the given test chemical (2 -methoxy ethyl) benzene (CAS no.: 3558 -60 -9, E.C. no.: 222 -619 -7) as per OECD Guideline 402 (Acute Dermal Toxicity) in Wistar rats was tested with 200 (G1-DRF), 1000 (G2-DRF) and 2000 (G3-DRF) mg/kg with 1 female each for the dose range finding study and 2 female for main study (G3). Approximately 24 hours before treatment, the hair on the dorsolateral thoracic surface of the skin was clipped (approximately 10 x 8 cm) with an electric clipper (Aesculap - Germany). Based on the individual body weight, the test item at the doses of 200, 1000 and 2000 mg/kg body weight, the undiluted test item was applied directly to the clipped skin of the animal to cover about 10% of the body surface of the animal (semi-occlusive). The area of application was covered with cotton gauze (size: Females: 8 x 5 cm of 6 ply) and it was secured in position by adhesive tape wound around the torso. The test item contact period with the skin was for 24 hours. After the 24 hours contact period, the dressing was removed, and the applied area was washed with deionized water and wiped dry using clean towels.All the rats were observed for clinical signs of toxicity and mortality for 14 days post application. In addition, the treatment site was observed at 24, 48 and 72 hours after removal of test item using the Draize criteria. There were no clinical signs and pre-terminal deaths (mortality) observed during the study. There were no skin reactions at the site of application at 24, 48 and 72 hours after test patch removal (as per draize method). All rats gained body weight throughout the observation period.No abnormality was detected at necropsy.Based on the present study results, the acute dermal LD50 value of the given test chemical is >2000 mg/kg body weight in female Wistar rats. Thus, according to CLP criteria for acute toxicity rating for the chemicals, it infers that the given test chemical does not classify as an acute dermal toxicant. CLP Classification: “Not classified”.