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EC number: 202-675-9 | CAS number: 98-51-1
- 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
Endpoint summary
Administrative data
Description of key information
ORAL
28-day study in rats (0, 1.5, 5, 15, 50 mg/kg bw/d by gavage), equivalent to OECD TG 407. (Nihon Bioresearch, Inc.,)
The LOAEL is 5 mg/kg bw for males and 15 mg/kg bw for females.
The NOEL is 1.5 mg/kg bw for males and 5 mg/kg bw for females.
DERMAL
No data are available.
INHALATION
26- week study in rats (ca. 0.15 or 0.3 mg/l) (Hine et al., 1954).
A NOAEL could not be established, based on adverse findings observed at both dose levels.
Key value for chemical safety assessment
Additional information
ORAL
In a subacute toxicity study (Nihon Bioresearch Inc., undated) p-tert-Butyltoluene (purity 95.93%) was administered to 12 Sprague-Dawley rats/sex/dose by gavage at dose levels of 0, 1.5, 5, 15, 50 mg/kg bw/day. Satellite groups were allowed a 14-day recovery. The study was conducted in accordance with Japanese testing guidelines for 28-day oral toxicity in rodents, equivalent to OECD TG 407.
No deaths occurred. No treatment-related clinical signs of toxicity were observed. Body weights and body weight gain were similar in all groups. Lower food consumption was noted in the 15 mg/kg males and in both sexes given 50 mg/kg. Higher water intake was noted in the males at 15 mg/kg and in both sexes at 50 mg/kg.
Hematology revealed shortened APTT (males; 5, 15, 50 mg/kg bw) and lower values for fibrinogen concentration (males; 5, 15, 50 mg/kg bw; females; 50 mg/kg bw) and prolonged PT (females; 50 mg/kg bw).
Blood chemical analysis, revealed decreased total protein (males; 5, 15, 50 mg/kg bw; females;15, 50 mg/kg bw), decreased albumin (males; 15, 50 mg/kg bw; females; 15, 50 mg/kg bw), decreased total cholesterol (males; 50 mg/kg bw; females; 15, 50 mg/kg bw), decreased triglycerides (males, 5, 15, 50 mg/kg bw; females 15, 50 mg/kg bw), increased AST (males; 5, 15, 50 mg/kg bw), increased A/G ratio (males; 15, 50 mg/kg bw), increased gamma-GTP (females; 15, 50 mg/kg bw), increased total bilirubin (males; 15, 50 mg/kg bw; females; 50 mg/kg bw), increased urea nitrogen (males; 5, 15, 50 mg/kg bw), increased creatinine (males; 50 mg/kg bw), increased inorganic phosphorus (males; 5, 15, 50 males; mg/kg bw), decreased sodium (males; 50 mg/kg bw), decreased potassium (females 50 mg/kg bw), and decreased calcium (females; 15, 50 mg/kg bw).
Urinalysis revealed a higher urinary volume (males; 15, 50 mg/kg bw; females, 50 mg/kg bw), a tendency for pH lowering (males, 50 mg/kg bw; females, 50 mg/kg bw), decreased urinary specific gravity (males, 50 mg/kg bw), and decreased protein (males, 50 mg/kg bw).
On organ weight measurement, the following changes were reported: increased absolute liver weights (males; 50 mg/kg bw; females, 15, 50 mg/kg bw), increased relative liver weights (males; 15, 50 mg/kg bw; females, 15, 50 mg/kg bw), increased relative kidney weights (female; 50 mg/kg bw), increased relative adrenals weights (female; 50 mg/kg bw), decreased absolute testis and epididymis weights (males; 50 mg/kg bw), decreased relative testis weights (males, 50 mg/kg bw), and decreased absolute ovary weights (females, 50 mg/kg bw).
No gross pathological findings were reported.
Histopathology revealed the following findings: hypertrophy of periportal hepatocytes (males and females; 50 mg/kg bw), atrophy of seminiferous tubules (males; 50 mg/kg bw), hyperplasia of Leydig cells (males; 50 mg/kg bw), decrease in sperm (males; 50 mg/kg bw). At the termination of recovery period, atrophy of seminiferous tubules in the testes and decrease in sperm in the epididymides were still evident in the males which had received 50 mg/kg bw.
The LOAEL is 5 mg/kg bw for males and 15 mg/kg bw for females.
The NOAEL is 1.5 mg/kg bw for males and 5 mg/kg bw for females.
This subacute toxicity study in the rat is acceptable and satisfies the guideline requirement for a subacute oral study (OECD 407) in rats.
DERMAL
No data are available.
INHALATION
In a subchronic inhalation toxicity study (Hine et al., 1954), p-tert-butyltoluene (purity not given) was administered to 10 female Long-Evans rats/sex/concentration by whole body exposure at concentrations of 25-30 ppm or 50-60 ppm (ca. 0.15 or 0.3 mg/l, respectively) 1, 2, 4, and 7 hours per day, 5 days/week for a total of 26 weeks; Half of the rats were sacrificed after 10 weeks of exposure.
The majority of exposed animals did not display any evidence of substance-related damage or abnormal behaviour. One of three high dose rats exposed for 7 h/d died after the 42nd exposure; the remaining two rats displayed injury at the front and hind limbs. During the study, clinical symptoms were limited to slight irritation of the eyes and slightly elevated respiratory rate. A time- and dose-related increase in relative liver and kidney weights was observed. Clinical laboratory investigations revealed a depression of erythropoiesis; however, this was not considered to be substance-related. No statistically significant changes in blood parameters were noted after 26 weeks of exposure, with exception of significantly decreased leukocyte counts observed in high dose rats treated for 2, 4, or 7 h/d.
At histopathological examination, chronic encephalomeningitis was observed in both low and high dose rats exposed for 4 and 7 h. Slight fatty degeneration of the liver was noted in individual high dose rats.
A NOAEL could not be established, based on adverse findings observed at both dose levels; the LOAEL was ca. 0.15 mg/l.
A classification of this subchronic toxicity study in the rat is not possible due to rather poor documentation. It cannot be stated if this study satisfies or does not satisfy the guideline requirement (OECD 412) for a subchronic inhalation study in the rat.
Justification for classification or non-classification
The effects observed at a dose level of 5 mg/kg bw/day after oral exposure and a concentration of 0.15 mg/l after inhalative exposure would lead to a classification for repeated dose oral toxicity (R48/20/22 or STOT repeated Cat. 1) according to the Directive 67/548/EC or GHS criteria.
However, due to the effects on the central nervous system observed after single inhalative administration of the substance at a dose level of 1,5 mg/l a classification with R39/23/24/25 or STOT single Cat 1 is warranted.
Due to this an additional classification regarding repeated dose toxicity is considered to be not appropriate.
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