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EC number: 249-636-2 | CAS number: 29450-45-1
- 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
Genetic toxicity: in vivo
Administrative data
- Endpoint:
- in vivo mammalian somatic cell study: cytogenicity / bone marrow chromosome aberration
- Type of information:
- experimental study
- Adequacy of study:
- key study
- Reliability:
- 1 (reliable without restriction)
- Rationale for reliability incl. deficiencies:
- guideline study
Cross-reference
- Reason / purpose for cross-reference:
- read-across source
Data source
Reference
- Reference Type:
- study report
- Title:
- Unnamed
- Year:
- 2 005
- Report date:
- 2005
Materials and methods
Test guideline
- Qualifier:
- according to guideline
- Guideline:
- OECD Guideline 475 (Mammalian Bone Marrow Chromosome Aberration Test)
- GLP compliance:
- yes (incl. QA statement)
- Type of assay:
- mammalian bone marrow chromosome aberration test
Test material
- Reference substance name:
- (4-chloro-2-methylphenoxy)acetic acid
- EC Number:
- 202-360-6
- EC Name:
- (4-chloro-2-methylphenoxy)acetic acid
- Cas Number:
- 94-74-6
- Molecular formula:
- C9H9ClO3
- IUPAC Name:
- (4-chloro-2-methylphenoxy)acetic acid
- Reference substance name:
- Water
- EC Number:
- 231-791-2
- EC Name:
- Water
- Cas Number:
- 7732-18-5
- Molecular formula:
- H2O
- IUPAC Name:
- water
- Reference substance name:
- 4-chloro-o-cresol
- EC Number:
- 216-381-3
- EC Name:
- 4-chloro-o-cresol
- Cas Number:
- 1570-64-5
- Molecular formula:
- C7H7ClO
- IUPAC Name:
- 4-chloro-2-methylphenol
- Test material form:
- solid
Constituent 1
impurity 1
impurity 2
- Specific details on test material used for the study:
- Tested compound and dose range
Test substance MCPA was prepared for administration as suspension of MCPA in 0,5% carboxymethylcellulose. The substance volumes (12.5 -100 mg/kg) for individual animals were chosen due to the individual body weights. The substance volumes (calculation) are recorded in the primary documentation.
Solvent: 0.5% carboxymethylcelullose
Auxiliary compound: Aqua pro injectione
Positive control
Cyclophosphamidum monohydricum (ENDOXAN) was used as positive control compound in this study. The compound was dissolved in sterile distilled water and immediately injected intraperitoneally (i.p.) into mice in a dosage 20 mg/kg, volume 10 ml/kg.
Test animals
- Species:
- mouse
- Strain:
- ICR
- Sex:
- male
- Details on test animals or test system and environmental conditions:
- Experimental animals
ICR-SPF mice: 49 males, 8 weeks old and weighing 28-34 g (Protocol 8/2004).Supplier of animals: Accredited Breeding Velaz Prague. Identification of animals: signing of cages with indicating sex, dose and date of compound application. Animal acclimatization: 7 days.
Animal care and use statement
The animals were housed in experimental animal room in standard cages. Hygiene of housing and animal nursing was carried out according to (SOP 1, 7). The animals were maintained under 12h light and dark cycles in a room in which the relative humidity was at 55-60 % and the temperature was maintained at 22 ± 2°C, controlled according to (SOP 8, 9). The mice were fed with a balanced diet ST (according to TOP DOVO Dobra Voda) and tap water ad libitum. The animals were placed into the animal room 412/C on the Department of microbiology in the day of the test performance.
All procedures were in compliance with the Animal Welfare Act, the Guide for the Care and Use of Laboratory Animals, and the Office of Laboratory Animal Welfare. In the opinion of responsible investigator, the partial study does not unnecessarily duplicate any previous work.
Administration / exposure
- Details on exposure:
- Dose
Acute oral LD50 values for MCPA of 550 and 700 mg /kg of body weight have been reported in mice and rats. Based on this parameter three doses of MCPA were selected for the genotoxic assay (12.5, 25 and 100 mg/kg). The used doses were 44, 22 and 5.5 times lower than the published LD50 values.
Results and discussion
Test results
- Key result
- Sex:
- male
- Genotoxicity:
- negative
- Toxicity:
- no effects
- Remarks:
- The used doses were 44, 22 and 5.5 times lower than the published LD50 acute tox values for MCPA.
- Vehicle controls validity:
- valid
- Negative controls validity:
- valid
- Positive controls validity:
- valid
Applicant's summary and conclusion
- Executive summary:
Bone marrow cells of male mice were used for in vivo cytogenetic analysis. The evaluation in a single sex was performed because there are expected no substantial differences in toxicity between sexes.
Five mice were examined in each experimental group and also in intact and (vehicle) group. Doses of up to 300 mg/kg were used in this experiment. The animals tolerated the highest dose with minimal symptoms of toxicity. In the group of animals treated with dose of 300 mg/kg was not possible to perform cytogenetic analysis because the numbers of mitoses were greatly diminished.
Oral administration of MCPA (25 and 100 mg/kg) induced a slight increase in the frequency of damaged cells and in the number of chromosome aberrations/cell over the level of control.
The results of statistical analysis did not show any significant differences in the percent aberrant metaphases exclusive of gaps between vehicle control (0.8 % of aberrant cells) and treated groups with MCPA at doses 25 and 100 mg/kg (1.8 %, 2.4 %). The percent aberrant metaphase exclusive of gaps in group mice treated with MCPA of 12,5 mg/kg was 0,6 %.
The metaphase analysis of the bone marrow cells revealed mostly the presence of chromatid gaps and chromatid breaks in MCPA treated animals.
The positive control compound cyclophosphamide gave a significantly higher percentage of aberrant metaphase cells, as compared with the vehicle control. Cyclophosphamide induced a number of chromosomal abnormalities, including chromosome breaks, chromatide breaks and chromatide exchanges.
Mitotic index (MI) was calculated from 1000 cells/ animal and expressed in percentage. The percentages of dividing cells exhibited by the groups of mice that received MCPA at doses 12.5, 25 and 100 mg/kg did not differ much from that of the vehicle group of mice. Statistically significant reduction of percentage of dividing cells in the positive control group was not observed.
Obtained results showed MCPA did not cause significant increase in the frequency of cells with chromosome aberrations and also chromosomal aberrations/cell in vivo. Under our testing conditions, MCPA doses of 12.5,25 and 100 mg/kg body weight did not show any mutagenic effect after cytogenetic analysis of bone marrow. The results suggest that MCPA has no genotoxic potential in vivo.
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