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Diss Factsheets
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EC number: 202-815-9 | CAS number: 100-06-1
- 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
Link to relevant study record(s)
- Endpoint:
- basic toxicokinetics, other
- Remarks:
- Expert Statement
- Type of information:
- other: Expert Statement
- Adequacy of study:
- key study
- Reliability:
- 1 (reliable without restriction)
- Rationale for reliability incl. deficiencies:
- other: Expert Statement, no study available
- Objective of study:
- absorption
- distribution
- excretion
- metabolism
- Principles of method if other than guideline:
- Expert statement
- GLP compliance:
- no
- Specific details on test material used for the study:
- not applicable
- Details on test animals or test system and environmental conditions:
- not applicable
- Duration and frequency of treatment / exposure:
- not applicable
- Positive control reference chemical:
- not applicable
- Details on study design:
- not applicable
- Details on dosing and sampling:
- not applicable
- Statistics:
- not applicable
- Details on absorption:
- Generally, oral absorption is favoured for molecular weights below 500 g/mol. The good water solubility of 1737 mg/L enables the substance to readily dissolve in the gastrointestinal fluids. In combination with the low molecular weight of less than 200 g/mol the molecules can pass through aqueous pores or can also be carried through the epithelial barrier by the bulk passage of water. The moderate log Pow value (between -1 and 4) is also favourable for passive diffusion. Taken together, the physiochemical properties indicate that the substance becomes bioavailable following the oral route. This assumption is confirmed by the results of the oral toxicity study, where mortality occurred.
Due to the low volatility (vapour pressure <0.5 kPa) of the substance it is unlikely that the substance will be available as a vapour to a large extend, but if it is the case absorption via inhalation route might be possible due to the water solubility and the moderate log Pow value, enabling uptake directly across the respiratory tract epithelium by passive diffusion.
Dermal absorption may also take place, favoured by the water solubility and the log Pow value, and also by the size of the molecule, even though the test results did not indicate this: No mortality occurred in an acute dermal toxicity study and no indications of a skin sensitising potential were revealed. The dermal permeability constant Kp was calculated to be 0.00348 cm/hr (Dermwin v.2.02). The test substance was found to be irritant to skin, indicating that dermal uptake might be facilitated by damaging the skin. - Details on distribution in tissues:
- The physicochemical properties of the substance favour systemic absorption following oral, inhalative and dermal uptake. The systemic absorption and distribution within the body is also demonstrated by the decreased viability index of PND 4 and decreased body weights on PND 13 of the F1 pups in the OECD 422 study.
Direct transport through aqueous pores is likely to be an entry route to the systemic circulation. After being absorbed into the body, the substance is most likely distributed into the interior part of cells due to its very slightly lipophilic properties (log Pow 1.79) and in turn the intracellular concentration may be slightly higher than extracellular concentration particularly in adipose tissues.
The log Pow of the test substance indicates no bioaccumulation potential as it is below 3 and the most likely uptake mechanism into cells is passive diffusion, therefore the test substance is not considered to be bioaccumulative. - Details on excretion:
- The test substance will be excreted most likely in its metabolised form. The likely excretion pathway of the test substance and its metabolites is via urine as substances with a molecular weight below 300 g/mol are prone to this pathway.
- Metabolites identified:
- yes
- Remarks:
- predicted yb QSAR Toolbox v4.2
- Details on metabolites:
- The in vitro rat liver metabolic simulator of QSAR toolbox v4.2 predicted formaldehyde, 1-(4-Hydroxyphenyl)ethanone, 1-(4-Methoxyphenyl)ethanol and formic acid as metabolites. Formaldehyde and will be further oxidized into formate and eventually to carbon dioxide. 1-(4-Hydroxyphenyl)ethanone and 1-(4-Methoxyphenyl)ethanol may further undergo conjugation reactions to facilitate excretion via urine.
- Conclusions:
- Bioaccumulation of the test substanceis not considered critical based on expert statement.
- Executive summary:
Based on physicochemical characteristics absorption by the oral and dermal route takes place. This assumption is supported by the results of the oral acute toxicity study, revealing mortality at <2000 mg/kg bw. Absorption via inhalation route is unlikely, but may also take place. Bioaccumulation of the substance is not expected.After being absorbed into the body,4’-methoxyacetophenone ismost likely distributed into the interior part of cells due to its very slightly lipophilic properties (log Pow 1.79) and in turn the intracellular concentration may be slightly higher than extracellular concentration particularly in adipose tissues. A metabolic activation to more toxic metabolites is not to be expected. Predicted metabolites formed in the liver and upon skin contact are presented above (QSAR tollbox v4.2). In general, phase I and II metabolism reactions will render the molecule more polar to faciliate excretion via urine.
Reference
Description of key information
Based on physicochemical characteristics absorption by the oral and dermal route takes place. This assumption is supported by the results of the oral acute toxicity study, revealing mortality at <2000 mg/kg bw. Absorption via inhalation route is unlikely, but may also take place. Bioaccumulation of the substance is not expected.After being absorbed into the body,4’-methoxyacetophenone ismost likely distributed into the interior part of cells due to its very slightly lipophilic properties (log Pow 1.79) and in turn the intracellular concentration may be slightly higher than extracellular concentration particularly in adipose tissues. A metabolic activation to more toxic metabolites is not to be expected. Predicted metabolites formed in the liver and upon skin contact are presented above (QSAR tollbox v4.2). In general, phase I and II metabolism reactions will render the molecule more polar to faciliate excretion via urine.
Key value for chemical safety assessment
- Bioaccumulation potential:
- no bioaccumulation potential
Additional information
4’-methoxyacetophenoneis a mono-constituent substance. It is a colourless to pale yellow waxy solid at room temperature with a molecular weight of150.18g/mol. The substance is soluble in water (1737 mg/L at 20 °C). The log Pow was determined to be 1.79 at 20 °C. The test substance has a vapour pressure of 0.42 Pa at 20 °C.
Absorption
Generally, oral absorption is favoured for molecular weights below 500 g/mol. The good water solubility of 1737 mg/L enables the substance to readily dissolve in the gastrointestinal fluids. In combination withthe low molecular weight of less than 200g/mol the molecules can pass through aqueous pores or can also be carried through the epithelial barrier by the bulk passage of water. The moderate log Pow value (between -1 and 4) is also favourable for passive diffusion. Taken together, the physiochemical properties indicate that 4’-methoxyacetophenone becomes bioavailable following the oral route. This assumption is confirmed by the results of the oral toxicity study, where mortality occurred.
Due to the low volatility (vapour pressure <0.5 kPa) of4’-methoxyacetophenoneit is unlikely that the substance will be available as a vapour to a large extend, but if it is the case absorption via inhalation route might be possible due to the water solubility and the moderate log Pow value, enabling uptake directly across the respiratory tract epithelium by passive diffusion.
Dermal absorption may also take place, favoured by the water solubility and the log Pow value, and also by the size of the molecule, even though the test results did not indicate this: No mortality occurred in an acute dermal toxicity study and no indications of a skin sensitising potential were revealed. The dermal permeability constant Kp was calculated to be 0.00348 cm/hr (Dermwin v.2.02). The test substance was found to be irritant to skin, indicating that dermal uptake might be facilitated by damaging the skin.
Distribution
As mentioned above, the physicochemical properties of 4’-methoxyacetophenone favour systemic absorption following oral, inhalative and dermal uptake. The systemic absorption and distribution within the body is also demonstrated by the decreased viability index of PND 4 and decreased body weights on PND 13 of the F1 pups in the OECD 422 study.
Direct transport through aqueous pores is likely to be an entry route to the systemic circulation. After being absorbed into the body,4’-methoxyacetophenoneis most likely distributed into the interior part of cells due to its very slightly lipophilic properties (log Pow 1.79) and in turn the intracellular concentration may be slightly higher than extracellular concentration particularly in adipose tissues.
The log Powof 4’-methoxyacetophenone indicates no bioaccumulation potential as it is below 3 and the most likely uptake mechanism into cells is passive diffusion, therefore the test substance is not considered to be bioaccumulative.
Metabolism
The genotoxicity studies indicatedno remarkable differences in regard to genotoxicity and cytotoxicity in the presence or absence of metabolic activation systems. Thus a metabolic activation to more toxic metabolites was not indicated.
By using the OECD QSAR Toolbox, the following metabolites were determined:
The in vitro rat liver metabolic simulator of QSAR toolbox v4.2 predicted the following metabolites:
Table 1: predicted rat liver metabolites
Formaldehyde
|
1-(4-Hydroxyphenyl)ethanone |
1-(4-Methoxyphenyl)ethanol |
Formic acid |
The skin metabolism simulator of QSAR toolbox v4.2 found the metabolites presented below.
Table 2: predicted skin metabolites
Formaldehyde |
1-(4-Hydroxyphenyl)ethanone |
Formic acid |
Formaldehyde will be further oxidized into formate and eventually to carbon dioxide. 1-(4-Hydroxyphenyl)ethanone and 1-(4-Methoxyphenyl)ethanol may further undergo conjugation reactions to facilitate excretion via urine.
Excretion
The test substance will be excreted most likely in its metabolised form. The likely excretion pathway of 4’-methoxyacetophenone and its metabolites is via urine as substances with a molecular weight below 300 g/mol are prone to this pathway.
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