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Diss Factsheets

Toxicological information

Acute Toxicity: oral

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Administrative data

Endpoint:
acute toxicity: oral
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Study performed according to GLP and guideline

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2007
Report date:
2007

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 423 (Acute Oral toxicity - Acute Toxic Class Method)
GLP compliance:
yes
Test type:
acute toxic class method

Test material

Constituent 1
Chemical structure
Reference substance name:
1,1'-(1,1-dimethyl-3-methylene-1,3-propanediyl)bisbenzene
EC Number:
228-846-8
EC Name:
1,1'-(1,1-dimethyl-3-methylene-1,3-propanediyl)bisbenzene
Cas Number:
6362-80-7
Molecular formula:
C18H20
IUPAC Name:
(4-methyl-4-phenylpent-1-en-2-yl)benzene
Details on test material:
- Name of test material (as cited in study report): 2,4-diphenyl-4-methyl-1-pentene
- Physical state: Liquid
- Analytical purity: 96.97%
- Lot/batch No.: 412220
- Impurities (identity and concentrations): 2,4-Diphenyl-4-methyl-2-pentene 2.54%
- Storage condition of test material: Room temperature protected from light

Test animals

Species:
rat
Strain:
Crj: CD(SD)
Sex:
female
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Source: Charles River Laboratories Japan (Hino Breeding Center)
- Age at study initiation: 8 weeks of age
- Weight at study initiation: 175-187 g.
- Fasting period before study: Animals were fasted from the evening of the day before administration (from 4:00-4:10 pm) for about 17.5-18.5 hours until administration, and then for about 6 hours after administration, after which feed was provided again
- Housing: The animals were housed individually in racks of 5 stainless steel cages (W: 755 × D: 210 × H: 170 mm) during both the quarantine/acclimation period and after grouping
- Diet: The animals had free access to pellet diet (CRF-1, Oriental Yeast Co., Ltd.)
- Water: The animals were provided free access to tap water in water bottles. However, water was removed after grouping for about 6 hours until administration, after which it was provided again.
- Acclimation period: A five day quarantine period followed by a 2 day acclimation period was set for the animals before the first, second, third and fourth tests

ENVIRONMENTAL CONDITIONS
- Temperature: 23°C (measured values: 21-23°C),
- Humidity: nominal humidity of 55% (measured values: 40-61%)
- Air changes (per hr): 12 times/hour (filter-sterilized fresh air).
- Photoperiod: 12-hour light/dark cycle (illumination: 6:00 am to 6:00 pm)

Administration / exposure

Route of administration:
oral: gavage
Vehicle:
corn oil
Details on oral exposure:
MAXIMUM DOSE VOLUME APPLIED:
The dose volume was 10 mL/kg, calculated based on the body weight measured immediately before administration.

CLASS METHOD (if applicable)
- Rationale for the selection of the starting dose: The LD50 value for oral administration of 2,4-diphenyl-4-methyl-1-pentene in rats is reported to be 3.8 mL/kg. 1) Therefore, the maximum dose of 2000 mg/kg according to the OECD Guideline for Testing of Chemical for Acute Oral Toxicity-Acute Toxic Class method (Revised Guideline 423) was selected for the first test.
Doses:
2000 and 300 mg/kg
No. of animals per sex per dose:
Three females
Control animals:
no
Details on study design:
- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: The animals were observed for clinical signs and mortality for 6 hours after administration (immediately after to 30 minutes after administration and 2, 4 and 6 hours after administration) and once a day during the observation period from the day after administration. Body weight was measured on the day of administration (immediately before administration) and 1, 3, 7, 10 and 14 days after administration
- Necropsy of survivors performed: yes

Results and discussion

Effect levels
Key result
Sex:
female
Dose descriptor:
LD50
Effect level:
300 - 2 000 mg/kg bw
Based on:
test mat.
Mortality:
One animal died on day 1 after administration in the first test at 2000 mg/kg, and 2 animals died on day 1 after administration in the second test at 2000 mg/kg. There were no deaths in the third and fourth tests at 300 mg/kg. From these results, the LD50 value of 2,4-diphenyl-4-methyl-1-pentene was estimated to be between 300 mg/kg and 2000 mg/kg.
Clinical signs:
other: Clinical signs observed in the first test at 2000 mg/kg were tremor in 1 animal at 4 hours after administration, tremor and clonic convulsions in 1 animal at 6 hours after administration, and soiled perineal region in 2 animals and clonic convulsions in 1
Gross pathology:
No abnormal necropsy findings were observed either in the animals that died in the first and second tests at 2000 mg/kg.

No abnormal necropsy findings were observed in the surviving animals in the first and second tests at 2000 mg/kg or in the surviving animals in the third and fourth tests at 300 mg/kg.

Any other information on results incl. tables

Results: (Test group 1: 1,1-(1,1-dimethyl-3-methylene-1,3-propanediyl) bisbenzene group at 2000 mg/kg)

Concentration of 1,1-(1,1-dimethyl-3-methylene-1,3-propanediyl) bisbenzene (mg/mL)

Measured concentrations

Recovery rate (%)

1st

2nd

Mean

200

192.2

196.1

194.2

97.1

The concentration of the preparation was within the acceptable range (100 ± 10%)

Results: (Test group 2: 1,1-(1,1-dimethyl-3-methylene-1,3-propanediyl) bisbenzene group at 2000 mg/kg)

Concentration of 1,1-(1,1-dimethyl-3-methylene-1,3-propanediyl) bisbenzene (mg/mL)

Measured concentrations

Recovery rate (%)

1st

2nd

Mean

200

194.6

186.4

190.5

95.3

The concentration of the preparation was within the acceptable range (100 ± 10%)

Results: (Test group 3: 1,1-(1,1-dimethyl-3-methylene-1,3-propanediyl) bisbenzene group at 300 mg/kg)

Concentration of 1,1-(1,1-dimethyl-3-methylene-1,3-propanediyl) bisbenzene (mg/mL)

Measured concentrations

Recovery rate (%)

1st

2nd

Mean

30

28.77

28.78

28.78

95.9

The concentration of the preparation was within the acceptable range (100 ± 10%)

Results: (Test group 4: 1,1-(1,1-dimethyl-3-methylene-1,3-propanediyl) bisbenzene group at 300 mg/kg)

Concentration of 1,1-(1,1-dimethyl-3-methylene-1,3-propanediyl) bisbenzene (mg/mL)

Measured concentrations

Recovery rate (%)

1st

2nd

Mean

30

29.88

29.31

29.60

98.7

The concentration of the preparation was within the acceptable range (100 ± 10%)

Applicant's summary and conclusion

Interpretation of results:
Category 4 based on GHS criteria
Conclusions:
The LD50 value of 2,4-diphenyl-4-methyl-1-pentene is estimated to be between 300 mg/kg and 2000 mg/kg. Based on the results the test substance should be classified as Acute Toxicity Category 4 according to CLP regulation 1272/2008

Respiratory paralysis or central nervous abnormality is thought to have led to deaths because tremor and clonic convulsions were observed following the administration of the test item at 2000 mg/kg.