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EC number: 921-042-4 | CAS number: 24085-06-1
- 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
Toxicological Summary
- Administrative data
- Workers - Hazard via inhalation route
- Workers - Hazard via dermal route
- Workers - Hazard for the eyes
- Additional information - workers
- General Population - Hazard via inhalation route
- General Population - Hazard via dermal route
- General Population - Hazard via oral route
- General Population - Hazard for the eyes
- Additional information - General Population
Administrative data
Workers - Hazard via inhalation route
Systemic effects
Long term exposure
- Hazard assessment conclusion:
- DNEL (Derived No Effect Level)
- Value:
- 4.9 mg/m³
- Most sensitive endpoint:
- repeated dose toxicity
- Route of original study:
- Oral
DNEL related information
- DNEL derivation method:
- other: ECHA Guidance and ECETOC TR no110
- Overall assessment factor (AF):
- 18
- Modified dose descriptor starting point:
- NOAEC
- Value:
- 88 mg/m³
- Explanation for the modification of the dose descriptor starting point:
- ECHA guidance recommends that an assessment factor of 2 be applied when doing route to route extrapolation for oral to inhalation exposure, recognizing higher absorption via the lungs. The NOAEL from the oral study was therefore divided by two before the route to route extrapolation. Allometric scaling is applied by taking account for the different breathing rates between rats and humans, as described in ECHA technical guidance the oral NOAEL in the rat mg/kg/day *1/0.38 * 6.7/10 = mg/m3 inhalation NOAEC for workers.
- AF for dose response relationship:
- 1
- Justification:
- No systemic or developmental effects were seen at the maximum dose tested
- AF for differences in duration of exposure:
- 6
- Justification:
- ECHA guidance document Chapter R8, in Appendix R.8-12, indicates that DNELS derived using a NOAEL from a 28 day study are derived using an assessment factor of 6 for extrapolation of the study duration to chronic exposure.
- AF for interspecies differences (allometric scaling):
- 1
- Justification:
- Allometric scaling is already included in the route to route extrapolation from the rat oral NOAEL to the equivalent human inhalation NOAEC.
- AF for other interspecies differences:
- 1
- Justification:
- ECETOC reported in 2010 after an extensive review (see discussion) that there is no justification for the suggested additional factor of 2.5 for this, therefore a factor of 1 has been applied.
- AF for intraspecies differences:
- 3
- Justification:
- ECETOC reported in 2010 after an extensive scientific review that the appropriate fact for intraspecies differences for workers is 3 and not 5 as ECHA proposed. See discussion for detailed justification.
- AF for the quality of the whole database:
- 1
- Justification:
- A full Annex VIII dataset is available for this substance, including a combined 28 day/reproductive screening study.
- AF for remaining uncertainties:
- 1
- Justification:
- All uncertainties are already included so a factor of 1 is applied.
Acute/short term exposure
- Hazard assessment conclusion:
- low hazard (no threshold derived)
- Most sensitive endpoint:
- acute toxicity
- Route of original study:
- Oral
DNEL related information
Local effects
Long term exposure
- Hazard assessment conclusion:
- medium hazard (no threshold derived)
Acute/short term exposure
- Hazard assessment conclusion:
- medium hazard (no threshold derived)
DNEL related information
Workers - Hazard via dermal route
Systemic effects
Long term exposure
- Hazard assessment conclusion:
- DNEL (Derived No Effect Level)
- Value:
- 1.4 mg/kg bw/day
- Most sensitive endpoint:
- repeated dose toxicity
- Route of original study:
- Oral
DNEL related information
- DNEL derivation method:
- other: ECHA Guidance and ECETOC TR no110
- Overall assessment factor (AF):
- 72
- Modified dose descriptor starting point:
- NOAEL
- Value:
- 100 mg/kg bw/day
- Explanation for the modification of the dose descriptor starting point:
- ECHA guidance assumes that absorption for dermal exposure is the same as for oral exposure, which is a worst case assumption.
- AF for dose response relationship:
- 1
- Justification:
- No systemic or developmental effects were seen at the maximum dose tested
- AF for differences in duration of exposure:
- 6
- Justification:
- ECHA guidance document Chapter R8, in Appendix R.8-12, indicates that NOAELs from a 28 day study should have a factor of 6 applied for extrapolation of the DNEL to chronic exposure.
- AF for interspecies differences (allometric scaling):
- 4
- Justification:
- A factor of 4 is applied based on ECHA guidance for allometric scaling of data from rats to humans.
- AF for other interspecies differences:
- 1
- Justification:
- ECETOC reported in 2010 after an extensive review (see discussion) that there is no justification for the suggested additional factor of 2.5 for this, therefore a factor of 1 has been applied.
- AF for intraspecies differences:
- 3
- Justification:
- ECETOC reported in 2010 after an extensive scientific review that the appropriate fact for intraspecies differences for workers is 3 and not 5 as ECHA proposed. See discussion for detailed justification.
- AF for the quality of the whole database:
- 1
- Justification:
- A full Annex VIII dataset is available for this substance, including a combined 28 day/reproductive screening study.
- AF for remaining uncertainties:
- 1
- Justification:
- All uncertainties are already included so a factor of 1 is applied.
Acute/short term exposure
- Hazard assessment conclusion:
- no DNEL required: short term exposure controlled by conditions for long-term
- Most sensitive endpoint:
- acute toxicity
- Route of original study:
- Dermal
DNEL related information
Local effects
Long term exposure
- Hazard assessment conclusion:
- DNEL (Derived No Effect Level)
- Value:
- 3.33 µg/cm²
- Most sensitive endpoint:
- sensitisation (skin)
DNEL related information
- DNEL derivation method:
- ECHA REACH Guidance
- Overall assessment factor (AF):
- 90
- Dose descriptor:
- other: LOAEL
- AF for dose response relationship:
- 3
- Justification:
- default AF for the extrapolation of the LOAEL to the NOAEL
- AF for differences in duration of exposure:
- 1
- Justification:
- Sensitisation induction can be considered to be a single exposure event, therefore no AF for duration of exposure is required.
- AF for interspecies differences (allometric scaling):
- 10
- Justification:
- ECHA guidance document Chapter R8, Appendix R.8-10 indicates that a default AF of 10 for interspecies variation is applied
- AF for other interspecies differences:
- 1
- Justification:
- included in the above AF
- AF for intraspecies differences:
- 3
- Justification:
- ECETOC reported in 2010 after an extensive scientific review that the appropriate fact for intraspecies differences for workers is 3 and not 5 as ECHA proposed. See discussion for detailed justification
- AF for the quality of the whole database:
- 1
- Justification:
- The Point of departure has been extrapolated from the existing data points of a reliable study using accepted methodologies- no furhter AF required
- AF for remaining uncertainties:
- 1
- Justification:
- All uncertainties are already included so a factor of 1 is applied.
Acute/short term exposure
- Hazard assessment conclusion:
- no DNEL required: short term exposure controlled by conditions for long-term
Workers - Hazard for the eyes
Local effects
- Hazard assessment conclusion:
- high hazard (no threshold derived)
Additional information - workers
Selection of Assessment factors for Intra – Inter species variation for workers
ECHA (2010) has produced guidance on the assessment factors to use to derive a DNEL for human exposure based the application of assessment factors (safety factors) to an NOAEL or LOAEL in animal studies.
The ECHA guidance proposes an assessment factor of 4 for the allometric scaling from rats to humans when calculating oral and dermal DNELs. However it then proposes an additional factor of 2.5 to cover remaining differences (uncertainties). There is no clear scientific justification for this additional factor. ECETOC in itsGuidance on Assessment Factors to Derive a DNEL(2010) reviewed the scientific evidence and concluded that the factor of 4 for rats was sufficient to cover the allometric scaling from rats to humans and any remaining differences are of intra-species rather than interspecies variability. Based on this, the additional assessment factor of 2.5 for inter-species variability will not be used.
This ECETOC guidance also reviewed the intra-species assessment factors, which ECHA proposed as 5 for workers and 10 for the general population. ECETOC originally proposed in 2003, based on the scientific evidence, that assessment factors of 3 for workers and 5 for the general population are sufficient for covering any intra-species variability, which includes the remaining differences factor of 2.5.
This was confirmed in the ECETOC (2010) Guidance.
After reviewing these proposals, we have adopted the proposal from ECETOC as our default assessment factors but consider possible additional factors on a case by case basis.
In this case we have decided to use an assessment factor of 3 for workers based on the ECETOC Guidance (ECETOC 2010).
References:
ECHA, 2010 Guidance on information requirements and chemical safety assessment Chapter R.8: Characterisation of dose [concentration]-response for human health. Version 2 December 2010
ECETOC, 2010Guidance on Assessment Factors to Derive a DNEL,Technical Report No.110,ISSN-0773-8072-110 (print),ISSN-2079-1562-110 (online), October 2010
General Population - Hazard via inhalation route
Systemic effects
Long term exposure
- Hazard assessment conclusion:
- no hazard identified
Acute/short term exposure
- Hazard assessment conclusion:
- no hazard identified
DNEL related information
Local effects
Long term exposure
- Hazard assessment conclusion:
- no hazard identified
Acute/short term exposure
- Hazard assessment conclusion:
- no hazard identified
DNEL related information
General Population - Hazard via dermal route
Systemic effects
Long term exposure
- Hazard assessment conclusion:
- no hazard identified
Acute/short term exposure
- Hazard assessment conclusion:
- no hazard identified
DNEL related information
Local effects
Long term exposure
- Hazard assessment conclusion:
- no hazard identified
Acute/short term exposure
- Hazard assessment conclusion:
- no hazard identified
General Population - Hazard via oral route
Systemic effects
Long term exposure
- Hazard assessment conclusion:
- no hazard identified
Acute/short term exposure
- Hazard assessment conclusion:
- no hazard identified
DNEL related information
General Population - Hazard for the eyes
Local effects
- Hazard assessment conclusion:
- no hazard identified
Additional information - General Population
No DNELs have been derived for exposure of the general public since the substance Diacetate compound EC No 921-042-4, CAS No 24085-06-1 is a pharmaceutical intermediate and no exposure of the General Population is anticipated.
Information on Registered Substances comes from registration dossiers which have been assigned a registration number. The assignment of a registration number does however not guarantee that the information in the dossier is correct or that the dossier is compliant with Regulation (EC) No 1907/2006 (the REACH Regulation). This information has not been reviewed or verified by the Agency or any other authority. The content is subject to change without prior notice.
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