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EC number: 202-443-7 | CAS number: 95-71-6
- Life Cycle description
- Uses advised against
- Endpoint summary
- Appearance / physical state / colour
- Melting point / freezing point
- Boiling point
- Density
- Particle size distribution (Granulometry)
- Vapour pressure
- Partition coefficient
- Water solubility
- Solubility in organic solvents / fat solubility
- Surface tension
- Flash point
- Auto flammability
- Flammability
- Explosiveness
- Oxidising properties
- Oxidation reduction potential
- Stability in organic solvents and identity of relevant degradation products
- Storage stability and reactivity towards container material
- Stability: thermal, sunlight, metals
- pH
- Dissociation constant
- Viscosity
- Additional physico-chemical information
- Additional physico-chemical properties of nanomaterials
- Nanomaterial agglomeration / aggregation
- Nanomaterial crystalline phase
- Nanomaterial crystallite and grain size
- Nanomaterial aspect ratio / shape
- Nanomaterial specific surface area
- Nanomaterial Zeta potential
- Nanomaterial surface chemistry
- Nanomaterial dustiness
- Nanomaterial porosity
- Nanomaterial pour density
- Nanomaterial photocatalytic activity
- Nanomaterial radical formation potential
- Nanomaterial catalytic activity
- Endpoint summary
- Stability
- Biodegradation
- Bioaccumulation
- Transport and distribution
- Environmental data
- Additional information on environmental fate and behaviour
- Ecotoxicological Summary
- Aquatic toxicity
- Endpoint summary
- Short-term toxicity to fish
- Long-term toxicity to fish
- Short-term toxicity to aquatic invertebrates
- Long-term toxicity to aquatic invertebrates
- Toxicity to aquatic algae and cyanobacteria
- Toxicity to aquatic plants other than algae
- Toxicity to microorganisms
- Endocrine disrupter testing in aquatic vertebrates – in vivo
- Toxicity to other aquatic organisms
- Sediment toxicity
- Terrestrial toxicity
- Biological effects monitoring
- Biotransformation and kinetics
- Additional ecotoxological information
- Toxicological Summary
- Toxicokinetics, metabolism and distribution
- Acute Toxicity
- Irritation / corrosion
- Sensitisation
- Repeated dose toxicity
- Genetic toxicity
- Carcinogenicity
- Toxicity to reproduction
- Specific investigations
- Exposure related observations in humans
- Toxic effects on livestock and pets
- Additional toxicological data
Acute Toxicity: oral
Administrative data
- Endpoint:
- acute toxicity: oral
- Type of information:
- experimental study
- Adequacy of study:
- key study
- Study period:
- 05.03.2018 -27.03.2018
- Reliability:
- 1 (reliable without restriction)
- Rationale for reliability incl. deficiencies:
- guideline study
Data source
Reference
- Reference Type:
- study report
- Title:
- Unnamed
- Year:
- 2 018
- Report date:
- 2018
Materials and methods
Test guideline
- Qualifier:
- according to guideline
- Guideline:
- OECD Guideline 423 (Acute Oral toxicity - Acute Toxic Class Method)
- Version / remarks:
- 2008
- Deviations:
- no
- GLP compliance:
- yes (incl. QA statement)
- Test type:
- acute toxic class method
- Limit test:
- no
Test material
- Reference substance name:
- 2-methylhydroquinone
- EC Number:
- 202-443-7
- EC Name:
- 2-methylhydroquinone
- Cas Number:
- 95-71-6
- Molecular formula:
- C7H8O2
- IUPAC Name:
- 2-methylbenzene-1,4-diol
- Test material form:
- solid: particulate/powder
Constituent 1
Test animals
- Species:
- rat
- Strain:
- Wistar
- Sex:
- female
- Details on test animals or test system and environmental conditions:
- Housing: animal room with monitoring conditions – 3 animals of one sex in one plastic breeding cage
Food: maintenance pelleted diet for rats and mice - Altromin for rats/mice, Manufacturer: Altromin Spezialfutter GmbH & Co. KG, Germany ad libitum
Water: drinking water ad libitum, quality corresponding to the Regulation No. 252/2004 of Czech Coll. of Law
Microclimatic conditions: room temperature 22 ± 3 °C, permanently monitored
relative humidity 30 – 70 %, permanently monitored
light period 12-hour light/12 hour dark
Bedding: shavings of soft wood
Administration / exposure
- Route of administration:
- oral: gavage
- Vehicle:
- olive oil
- Details on oral exposure:
- The test item was administered to the stomach by tube. The single volume of administered suspension was 1 mL/100 g of animal body weight.
- Doses:
- The starting dose was 50 mg/kg of body weight.
- No. of animals per sex per dose:
- 3 animals per dose
- Control animals:
- no
- Details on study design:
- Test procedure with a starting dose of 50 mg/kg was selected. This level was chosen as a starting dose because there was information about toxicity of the test item. The test item in this dose level was administered sequentially to one group of 3 females. No death of animals was observed therefore the testing was continued with higher dose 300 mg/kg (application with time distance 24 hours). Because no death of animals was observed, next step using the higher dose 2000 mg/kg was performed (application with time distance 5 days). Because this dose caused a death of one female and two females were humanely killed for moribund status, the dose level was reduced to 300 mg/kg of body weight and applied to one group of 3 females. No death of animals was observed therefore the testing was finished.
Results and discussion
Effect levels
- Key result
- Sex:
- female
- Dose descriptor:
- LD50
- Effect level:
- > 2 000 mg/kg bw
- Based on:
- test mat.
- Mortality:
- The test item administered at the dose of 2000 mg/kg caused death of one animal and two animals were humanely killed by reason of moribund condition a few minutes after application of the test item. The clinical signs of intoxication such as anaemic appearance of the skin and visible mucous membranes, strong tremors and paralysis were observed 2 minutes after application of the test item in all three animals. During pathological examination the anaemic appearance of the skin and visible mucous membranes and the changes in the stomach as wrinkled mucosa of whitish colour were observed in all animals.
- Clinical signs:
- other: No serious clinical signs of intoxication were detected during whole study at the dose level 50 mg/kg (see table No. 2). At the dose level 300 mg/kg only the piloerection in all females was observed just during the first observations period (30 minutes) a
- Gross pathology:
- No pathologic macroscopic changes were diagnosed during pathological examination at the dose levels 50 and 300 mg/kg (see table No.6, No.7 and No.9).
During pathological examination the anaemic appearance of the skin and visible mucous membranes and the changes in the stomach as wrinkled mucosa of whitish colour were observed in all females at the dose level 2000 mg/kg (see table No.8)
Any other information on results incl. tables
Table No. 1: Individual body weight (g)
Dose mg/kg (Step No.) |
Animal No. |
Body weight (g) |
Body weight gain (g) |
||||
Before |
8th day |
15th day |
1st-8th day |
8th-15th day |
1st-15th day |
||
50 (1) |
1 |
172.16 |
206.48 |
217.43 |
34.32 |
10.95 |
45.27 |
2 |
155.71 |
179.26 |
197.44 |
23.55 |
18.18 |
41.73 |
|
3 |
166.09 |
203.77 |
229.17 |
37.68 |
25.40 |
63.08 |
|
mean |
164.65 |
196.50 |
214.68 |
31.85 |
18.18 |
50.03 |
|
SD |
8.32 |
15.00 |
16.04 |
7.38 |
7.23 |
11.44 |
|
300 (2) |
4 |
177.10 |
200.90 |
223.58 |
23.80 |
22.68 |
46.48 |
5 |
178.77 |
211.32 |
233.11 |
32.55 |
21.79 |
54.34 |
|
6 |
181.06 |
214.14 |
225.23 |
33.08 |
11.09 |
44.17 |
|
mean |
178.98 |
208.79 |
227.31 |
29.81 |
18.52 |
48.33 |
|
SD |
1.99 |
6.97 |
5.09 |
5.21 |
6.45 |
5.33 |
|
2000 (3) |
7 |
200.21 |
- |
- |
- |
- |
- |
8 |
178.10 |
- |
- |
- |
- |
- |
|
9 |
186.15 |
- |
- |
- |
- |
- |
|
mean |
188.15 |
- |
- |
- |
- |
- |
|
SD |
11.19 |
- |
- |
- |
- |
- |
|
300 (4) |
10 |
163.02 |
192.51 |
208.88 |
29.49 |
16.37 |
45.86 |
11 |
176.06 |
206.15 |
211.76 |
30.09 |
5.61 |
35.70 |
|
12 |
173.18 |
220.37 |
235.55 |
47.19 |
15.18 |
62.37 |
|
mean |
170.75 |
206.34 |
218.73 |
35.59 |
12.39 |
47.98 |
|
SD |
6.85 |
13.93 |
14.64 |
10.05 |
5.90 |
13.46 |
Note: p.a. – post application; SD – standard deviation
Table No. 2: Clinical observation – 50 mg/kg (Step No.1)
Animal No. |
Death after application |
Observed changes |
1 |
No |
30 minutes: no clinical signs of intoxication 3 hours:no clinical signs of intoxication 2nd– 14thday: no clinical signs of intoxication |
2 |
No |
30 minutes: no clinical signs of intoxication 3 hours:no clinical signs of intoxication 2nd– 14thday: no clinical signs of intoxication |
3 |
No |
30 minutes: no clinical signs of intoxication 3 hours:no clinical signs of intoxication 2nd– 14thday: no clinical signs of intoxication |
Table No. 3: Clinical observation – 300 mg/kg (Step No.2)
Animal No. |
Death after application |
Observed changes |
4 |
No |
30 minutes: piloerection 3 hours: piloerection 2nd– 14thday: no clinical signs of intoxication |
5 |
No |
30 minutes: piloerection 3 hours: piloerection 2nd– 14thday: no clinical signs of intoxication |
6 |
No |
30 minutes: piloerection 3 hours: piloerection 2nd– 14thday: no clinical signs of intoxication |
Table No. 4: Clinical observation – 2000 mg/kg (Step No.3)
Animal No. |
Death after application |
Observed changes |
7 |
Yes |
After application (approx. 2 minutes): anaemic appearance of the skin and visible mucous membranes,strong tremors, paralysis 30 minutes: - 3 hours:- 2nd– 14thday: - |
8 |
Humanely killed*
|
After application (approx. 2 minutes): anaemic appearance of the skin and visible mucous membranes,strong tremors, paralysis 30 minutes: - 3 hours:- 2nd– 14thday: - |
9 |
Humanely killed*
|
After application (approx. 2 minutes): anaemic appearance of the skin and visible mucous membranes,strong tremors, paralysis 30 minutes: - 3 hours:- 2nd– 14thday: - |
*The females were humanely killed a few minutes after applicationby reason of moribund condition.
Table No. 5: Clinical observation – 300 mg/kg (Step No.4)
Animal No. |
Death after application |
Observed changes |
10 |
No |
30 minutes: piloerection 3 hours: piloerection 2nd– 14thday: no clinical signs of intoxication |
11 |
No |
30 minutes: piloerection 3 hours: piloerection 2nd– 14thday: no clinical signs of intoxication |
12 |
No |
30 minutes: piloerection 3 hours: piloerection 2nd– 14thday: no clinical signs of intoxication |
Table No. 6: Pathological examination – 50 mg/kg (Step No. 1)
Animal No. |
Necropsy findings |
1 |
Without pathologic changes |
2 |
Without pathologic changes |
3 |
Without pathologic changes |
Table No. 7: Pathological examination – 300 mg/kg (Step No. 2)
Animal No. |
Necropsy findings |
4 |
Without pathologic changes |
5 |
Without pathologic changes |
6 |
Without pathologic changes |
Table No. 8: Pathological examination – 2000 mg/kg (Step No. 3)
Animal No. |
Necropsy findings |
7 |
External examination: anaemicappearance of the skin and visible mucous membranes Internal examination: Stomach - wrinkled mucosa ofwhitish colour |
8 |
External examination: anaemicappearance of the skin and visible mucous membranes Internal examination: Stomach - wrinkled mucosa ofwhitish colour |
9 |
External examination: anaemicappearance of the skin and visible mucous membranes Internal examination: Stomach - wrinkled mucosa ofwhitish colour |
Table No.9: Pathological examination – 300 mg/kg (Step No.4)
Animal No. |
Necropsy findings |
10 |
Without pathologic changes |
11 |
Without pathologic changes |
12 |
Without pathologic changes |
Applicant's summary and conclusion
- Interpretation of results:
- GHS criteria not met
- Conclusions:
- In an Acute Toxic Class Method-test according to OECD test guideline 423 the LD50 (oral) of the test item, Methylhydroquinone, for rats was determined to be >2000 mg/kg.
- Executive summary:
The test item toxicity was evaluated on the basis of mortality, clinical signs of intoxication, body weight increments during the observation period and necropsy findings at the end of study.
The test item administered at the dose of 50 and 300 mg/kg caused no death of animals. No serious clinical signs of intoxication were detected at these doses during whole study. At the dose level 300 mg/kg only the piloerection in all females was observed just during the first observations period (30 minutes) and also after 3 hours after application of the test item.
No pathologic macroscopic changes were diagnosed during pathological examination.
The test item administered at the dose of 2000 mg/kg caused death of one animal and two animals were humanely killed by reason of moribund condition a few minutes after application of the test item. The clinical signs of intoxication such as anaemic appearance of the skin and visible mucous membranes, strong tremors and paralysis were observed 2 minutes after application of the test item in all three animals. During pathological examination the anaemic appearance of the skin and visible mucous membranes and the changes in the stomach as wrinkled mucosa of whitish colour were observed in all animals.
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