Registration Dossier

Diss Factsheets

Administrative data

Endpoint:
acute toxicity: dermal
Type of information:
experimental study
Adequacy of study:
key study
Study period:
From October 14, 2020 to November 11, 2020
Reliability:
1 (reliable without restriction)

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2021

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 402 (Acute Dermal Toxicity: Fixed Dose Procedure)
Version / remarks:
9 October 2017
Deviations:
no
GLP compliance:
yes (incl. QA statement)
Test type:
fixed dose procedure
Limit test:
yes

Test material

Constituent 1
Chemical structure
Reference substance name:
1,4-bis(methoxymethyl)benzene
EC Number:
229-828-2
EC Name:
1,4-bis(methoxymethyl)benzene
Cas Number:
6770-38-3
Molecular formula:
C10H14O2
IUPAC Name:
1,4-bis(methoxymethyl)benzene
Test material form:
liquid

Test animals

Species:
rat
Strain:
Sprague-Dawley
Sex:
female
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Rationale for alternative/additional species to rat (if applicable)
- Source: SPF (Beijing) Biotechnology Co., Ltd
- Females (if applicable) nulliparous and non-pregnant: yes
- Rationale for use of males (if applicable)
- Age at study initiation: 56 days on arrival, in the range of 61~89 days at the commencement of each animal’s dosing.
- Weight at study initiation: The body weight ranges were 201~213 g at arrival, the body weight ranges were 219~274 g at grouping.
- Fasting period before study:
- Housing: Animals were housed in Room D104 of the facility. Animals were raised in suspended, stainless steel cages (L32.0 cm ×W60.0 cm×H20.0 cm) on cage racks (L199.0 cm×W70.0 cm×H171.0 cm). Animals were housed individually during the exposure period and returned to group-caging after that.
- Historical data:
- Diet (e.g. ad libitum): Animals were provided with SPF Rodent Maintenance Feed supplied by Shenyang Maohua Biotechnology Co., Ltd. Diet and water were available to the animals ad libitum during test.
- Water (e.g. ad libitum): Drinking water was purified by HT-RO1000 purity system. Diet and water were available to the animals ad libitum during test.
- Acclimation period: 5 days
- Microbiological status when known
- Method of randomisation in assigning animals to test and control groups

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22.8-24.9 ℃ (target value was 20-25℃)
- Humidity (%): 43%-68% (target value was 40%-70%)
- Air changes (per hr):
- Photoperiod (hrs dark / hrs light): A controlled light cycle was 12 hours light, 12 hours dark.

Administration / exposure

Type of coverage:
occlusive
Vehicle:
unchanged (no vehicle)
Details on dermal exposure:
TEST SITE
- Area of exposure: 40 cm2
- % coverage: 100%
- Type of wrap if used: The gauze was placed over the treatment area and was wrapped with a piece of self-adhesive bandage.

REMOVAL OF TEST SUBSTANCE
- Washing (if done): At the end of the exposure period for approximate 24 hours, residual test item was removed by cotton wool soaked in water.
- Time after start of exposure: approximate 24 hours

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): Because the test item is liquid, test item was administered as supplied at a variable dose volume. Before administration the theoretical test item used for each animal was calculated according to dose design and animal body weight: Dosing Volume (mL) = Body Weight (kg) × Dose (mg/kg) / Density (mg/mL).
Duration of exposure:
24 hours
Doses:
Range-finding study: 200, 1000 and 2000 mg/kg b.w.
Main study: 2000 mg/kg b.w.
No. of animals per sex per dose:
Range-finding study: 1 female
Main study: 2 females
Control animals:
no
Details on study design:
- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Moribund or mortality inspections were made twice daily for each animal, in the morning and in the afternoon, during normal working days, and once daily at weekends and public holidays.
- Necropsy of survivors performed: Animals surviving to the end of the study were anesthetized by CO2 and bled by abdominal aorta to death. Their corpse treatments were entrusted to specialized agencies.
At the end of the test, a gross necropsy was performed on all animals under test. The necropsy included carefully eye examinations of the skin of the dorsal area, the abdominal, thoracic organs and their contents of all animals.
- Clinical signs including body weight: Clinical observations were performed once during the first 30 minutes and at 1, 2, 4 and 6 hours after application approximately and then once each day for 14 days.
General observations were made once daily for the animals have not been administrated with the test item.
Careful observations and records of animal fur changes, eyes and mucosa, respiratory, circulatory, nervous system, particularly limb activity and behavior changes were made. Particular attention was directed to observations of tremor, convulsions, salivation, diarrhea, lethargy, sleep and coma.
Individual weights of animals were determined within 24 hours after arrival, at the end of adaption period, at grouping (the day before each animal's dosing day), on Day 0 (day of dosing), Day 7 and Day 14 or at death. Changes in weights were calculated and recorded.
Statistics:
Using the results obtained, the percutaneous toxicity characteristics and dermal toxicity LD50 range for the test item were evaluated. According to GHS criteria for the acute dermal toxicity, the test item category was given.

Results and discussion

Preliminary study:
After the test animals in the dose range-finding study were assured to be alive, a main study with dose level of 2000 mg/kg b.w. was carried out.
Effect levels
Key result
Sex:
female
Dose descriptor:
LD50
Effect level:
> 2 000 mg/kg bw
Based on:
test mat.
Mortality:
No deaths or moribund status were found in all animals during the test.
Clinical signs:
No symptoms were found in all animals' administration skin during the test.
Body weight:
The results indicated that all the body weight gains of animals showed a growing trend.
Gross pathology:
No abnormalities were found in all animals at necropsy.

Applicant's summary and conclusion

Interpretation of results:
GHS criteria not met
Conclusions:
The acute dermal LD50 in rats for the test item was estimated to be more than 2000 mg/kg b.w. in female SD rats.
Executive summary:

The study was performed to assess the acute dermal toxicity of test item in Sprague Dawley rats. The method was designed to meet the OECD Guideline for Testing of Chemicals: Acute Dermal Toxicity: Fixed Dose Procedure.


Based on the results, dermal administration of the test item can be tolerated in animal. The acute dermal LD50 in rats for the test item was estimated to be more than 2000 mg/kg b.w. in female SD rats. According to the GHS’s classification criteria of acute dermal toxicity, the test item was classified as “Category 5” or “Unclassified”.