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Diss Factsheets
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EC number: 277-633-6 | CAS number: 73912-21-7
- 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:
- 164 mg/m³
- Most sensitive endpoint:
- effect on fertility
- Route of original study:
- Oral
DNEL related information
- DNEL derivation method:
- ECHA REACH Guidance
- Overall assessment factor (AF):
- 75
- Dose descriptor starting point:
- NOAEL
- Value:
- 1 000 mg/kg bw/day
- Modified dose descriptor starting point:
- NOAEC
- Value:
- 12 300 mg/m³
- Explanation for the modification of the dose descriptor starting point:
Default (DNEL calculator)
- AF for dose response relationship:
- 1
- Justification:
- Default (DNEL calculator)
- AF for differences in duration of exposure:
- 6
- Justification:
- Default (DNEL calculator)
- AF for interspecies differences (allometric scaling):
- 1
- Justification:
- Default (DNEL calculator)
- AF for other interspecies differences:
- 2.5
- Justification:
- Default (DNEL calculator)
- AF for intraspecies differences:
- 5
- Justification:
- Default (DNEL calculator)
- AF for the quality of the whole database:
- 1
- Justification:
- Default (DNEL calculator)
- AF for remaining uncertainties:
- 1
- Justification:
- no remaining uncertainties
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
Workers - Hazard via dermal route
Systemic effects
Long term exposure
- Hazard assessment conclusion:
- DNEL (Derived No Effect Level)
- Value:
- 23.3 mg/kg bw/day
- Most sensitive endpoint:
- effect on fertility
- Route of original study:
- Oral
DNEL related information
- DNEL derivation method:
- ECHA REACH Guidance
- Overall assessment factor (AF):
- 300
- Dose descriptor starting point:
- NOAEL
- Value:
- 1 000 mg/kg bw/day
- Modified dose descriptor starting point:
- NOAEL
- Value:
- 7 000 mg/kg bw/day
- Explanation for the modification of the dose descriptor starting point:
Default (DNEL calculator)
- AF for dose response relationship:
- 1
- Justification:
- Default (DNEL calculator)
- AF for differences in duration of exposure:
- 6
- Justification:
- Default (DNEL calculator)
- AF for interspecies differences (allometric scaling):
- 4
- Justification:
- Default (DNEL calculator)
- AF for other interspecies differences:
- 2.5
- Justification:
- Default (DNEL calculator)
- AF for intraspecies differences:
- 5
- Justification:
- Default (DNEL calculator)
- AF for the quality of the whole database:
- 1
- Justification:
- Default (DNEL calculator)
- AF for remaining uncertainties:
- 1
- Justification:
- no remaining uncertainties
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
Workers - Hazard for the eyes
Local effects
- Hazard assessment conclusion:
- no hazard identified
Additional information - workers
The calculation of the DNELs is performed in accordance with the principles given in ECHA (2008) “Guidance of Information Requirements and Chemical Safety Assessment, Chapter R.8: Characterisation of dose [concentration]-response for human health.” and performed when enabled with the tool, by using the IUCLID 6 DNEL calculator.
Available dose descriptors:
For 4,8-dicyclohexyl-6-hydroxy-2,10-dimethyl-12H-dibenzo[d,g][1,3,2]dioxaphosphocin, DNELs are needed for chronic exposure by the oral (only for consumers), dermal (for workers and consumers) and inhalation routes of exposure (workers and consumers). Inhalation is not a relevant route of exposure due to the low vapour pressure and the physical state in combination with the form (handled as pellets only) and precautionary measures of the substance. Since 4,8-dicyclohexyl-6-hydroxy-2,10-dimethyl-12H-dibenzo[d,g][1,3,2]dioxaphosphocin does not represent an acute hazard (LD50(oral) > 2000 mg/kg / LD0(oral) > 2000 mg/kg / LD50(oral) > 1000 mg/kg / LD0(oral) ≥ 1000 mg/kg / LD50(dermal) > 2000 mg/kg / LD0(dermal) ≥ 2000 mg/kg), no DNELs for acute systemic toxicity need to be derived.
No DNELs are needed for local effects because there is no dose-response and route-specific information on these endpoints, and no skin or eye irritating effects were observed. Long-term systemic DNELs cover sufficiently local effects.
From all available data for the different human health endpoints it is clear that 4,8-dicyclohexyl-6-hydroxy-2,10-dimethyl-12H-dibenzo[d,g][1,3,2]dioxaphosphocin exerts its effect by a threshold mode of action. Thus, DNELs can be calculated for the different threshold endpoints based on the most relevant dose descriptors per endpoint. DNELs are derived based on the available toxicity data for the substance, reflecting the routes, duration and frequency of exposure. DNELs are derived for workers and the general population. The general population includes consumers and humans exposed via the environment. There are following annotations for each endpoint:
- Since the substance is not acutely toxic by oral route of exposure, no DNEL needs to be derived. This is based on a LD50(oral) > 2000 mg/kg / LD0(oral) > 2000 mg/kg resp. LD50(oral) > 1000 mg/kg / LD0(oral) ≥ 1000 mg/kg / LD50(dermal) > 2000 mg/kg resp. LD0(dermal) ≥ 2000 mg/kg (as evident from the available studies incl. estimated absorption parameters).
- Acute DNELs for inhalation (systemic and local) are not necessary since there is no acute toxic hazard by inhalation as described above.
- A qualitative approach in hazard assessment for eye and skin irritation/corrosion and skin sensitization is used because no quantitative dose descriptors are available on these endpoints. There is no skin or eye irritating nor skin sensitization potential
- There is no animal data on repeated dermal or inhalation exposure. To cover this endpoint, data from both an oral OECD 407 resp. 421 toxicity study in rats as most sensitive endpoint has been used to calculate the long-term DNELs.
- No DNELs for reprotoxic effects are derived because no evidence for toxicity to reproduction or development is available, the derived NOAELs of 1000 mg/kg bw/d (limit dose) are identical for reproductive and repeated dose toxicity effects.
First of all, available dose descriptors were converted into a correct starting point to take into account differences in routes of exposure between experimental animals and humans and differences in human and animal exposure conditions. Consecutively, the assessment factors have been applied to the correct starting point to obtain the endpoint specific DNELs. Assessment factors (AFs) correct uncertainties and variability within and between species in the effect data.
The assessment factors are applied in accordance with R.8 ECHA guidance document.
Modification of the relevant dose descriptors to the correct starting point:
Bioavailability (absorption)
A dermal absorption rate of 10% is considered for the target substance as outlined in the subchapter “Basic Toxicokinetics”, based on the available physico-chemical and toxicological properties of the substance. The dermal absorption in rats and in humans is assumed to be the same since no experimentally determined values are available for dermal absorption of the target chemical in rats and in humans. In case of oral to inhalation extrapolation, 50% absorption is assumed for oral absorption in rats and 10% absorption for inhalation is assumed in humans.
Route-to-route extrapolation:
Oral-to-inhalation extrapolations are performed to assess long-term inhalation effects in humans, as well as oral-to-dermal extrapolations are conducted to assess long-term dermal effects in humans. This is due to the fact that only oral studies are available, because oral exposure in general is the most suitable administration route to assess systemic toxicity.
Exposure conditions:
Exposure time differs in workers and in the 6-7 week (subacute) oral study in rats. Rats were exposed to the test substance once a day via gavage, while workers are exposed 8h daily (5 days/week). However, the dose descriptor (the NOAEL of 1000 mg/kg bw/d) was not adjusted to 8h exposure because exposure time is not really relevant for the systemic dose resulting from only dermal exposure. However, assuming a dose- and not concentration-dependent NOAEL, as further described in the Manual for the SECO-DNEL Tool 1.0 issued by the Swiss EAER, differences in experimental and human exposure conditions are taken into account as follows: Animals are dosed with the test item in repeated dose toxicity studies daily 7 days a week, whereas workers are only exposed 5 days a week on working days. Hence, the starting NOAEL is corrected with the factor 7 days / 5 days = 1.4.
Respiratory volumes:
Differences in the respiratory volumes between experimental animals and humans were considered when an oral rat NOAEL from the OECD 407 and 421 oral study in rats was used to assess inhalation exposure in humans. 0.38 m³/kg/day is the standard respiratory volume in rats (250 g) during 8h exposure, which is the average working and hence potential exposure time of workers. For workers with an assumed body weight of 70 kg, 6.7 and 10 m³ are standard respiratory volumes under normal conditions and by light activity, respectively.
Applying of assessment factors:
Interspecies differences:
No allometric scaling factor is applied in case of oral-to-inhalation extrapolation.
An additional assessment factor of 2.5 is applied for remaining interspecies differences in toxicodynamics between rats and humans.
Intraspecies differences:
An assessment factor of 5 is applied for workers for all endpoints and for all exposure routes. The factor of 10 is used in the process of DNEL-calculation for general population due to the greater intra-species variations.
Extrapolation of duration:
An assessment factor of 6 was applied in case of the 4 week oral repeated dose / 6-7 week reproductive toxicity study. This is a default assessment factor for subacute to chronic extrapolation according to ECHA’s guidance R.8 and no reason for deviation was identified.
Quality of whole data base:
An assessment factor for uncertainties in the quality of the data base is regarded to be 1, because no concern was indicated upon the quality of the provided data.
Issues related to dose response:
An assessment factor of 1 was used because there were no indications for deviation from the default value, no adverse responses at all were seen in the OECD 407 and 421 studies.
Remaining uncertainties:
An assessment factor of 1 was applied here because no remaining uncertainties were identified, as the chosen NOAEL was considered as a sufficiently safe approach, taking into account the slightly prolonged study duration (6-7 weeks compared to 4 weeks), the fact that the females were pregnant, and the fact that both the OECD 407 and 421 study revealed consistently a NOAEL = 1000 mg/kg bw/d.
Calculation of endpoint-specific DNELs for workers
Long-term exposure - systemic effects (dermal)
The oral NOAEL of 1000 mg/kg bw was converted into the dermal NOAEL: Dermal NOAEL = oral NOAEL x (ABS oral-rat/ABS dermal-human) x (exposure animals / exposure workers) = 1000 mg/kg bw x (50%/10%) x 1.4 = 7000 mg/kg bw.
DNEL = 7000 mg/kg bw/(1 x 6 x 4 x 2.5 x 5 x 1 x 1) = 23.33 mg/kg bw.
Assessment factors are: 1 – dose response (clear dose response), 6 – study duration (subacute to chronic), 4 – interspecies, allometric scaling, 2.5 – remaining interspecies differences, 5 – intraspecies (workers), 1 – quality of data base, 1 – remaining uncertainties (none remaining).
Long-term exposure - systemic effects (inhalation)
The oral NOAEL of 1000 mg/kg bw was converted into the inhalation NOAEC:
Inhalation NOAEC = oral NOAEL x (1/sRVrat) x (ABS oral-rat/ABS inhal-human) x (6.7 m³/10 m³) x (exposure animals / exposure workers) = 1000 mg/kg bw x (1/0.38 m³/kg/day) x (50%/10%) x (6.7/10) x 1.4 = 12342 mg/m³
DNEL = 12342 mg/m³/(1 x 6 x 1 x 2.5 x 5 x 1 x 1) = 164.56 mg/m³.
Assessment factors are: 1 – dose response (clear dose response), 6 – study duration (subacute to chronic), 1 – interspecies, no allometric scaling required for oral to inhalation exposure, 2.5 – remaining interspecies differences, 5 – intraspecies (workers), 1 – quality of data base, 1 – remaining uncertainties (none remaining).
General Population - Hazard via inhalation route
Systemic effects
Long term exposure
- Hazard assessment conclusion:
- DNEL (Derived No Effect Level)
- Value:
- 29 mg/m³
- Most sensitive endpoint:
- effect on fertility
- Route of original study:
- Oral
DNEL related information
- DNEL derivation method:
- ECHA REACH Guidance
- Overall assessment factor (AF):
- 150
- Dose descriptor starting point:
- NOAEL
- Value:
- 1 000 mg/kg bw/day
- Modified dose descriptor starting point:
- NOAEC
- Value:
- 4 350 mg/m³
- Explanation for the modification of the dose descriptor starting point:
Default (DNEL calculator)
- AF for dose response relationship:
- 1
- Justification:
- Default (DNEL calculator)
- AF for differences in duration of exposure:
- 6
- Justification:
- Default (DNEL calculator)
- AF for interspecies differences (allometric scaling):
- 1
- Justification:
- Default (DNEL calculator)
- AF for other interspecies differences:
- 2.5
- Justification:
- Default (DNEL calculator)
- AF for intraspecies differences:
- 10
- Justification:
- Default (DNEL calculator)
- AF for the quality of the whole database:
- 1
- Justification:
- Default (DNEL calculator)
- AF for remaining uncertainties:
- 1
- Justification:
- no uncertainties remaining
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:
- DNEL (Derived No Effect Level)
- Value:
- 8.33 mg/kg bw/day
- Most sensitive endpoint:
- effect on fertility
- Route of original study:
- Oral
DNEL related information
- DNEL derivation method:
- ECHA REACH Guidance
- Overall assessment factor (AF):
- 600
- Dose descriptor starting point:
- NOAEL
- Value:
- 1 000 mg/kg bw/day
- Modified dose descriptor starting point:
- NOAEL
- Value:
- 5 000 mg/kg bw/day
- Explanation for the modification of the dose descriptor starting point:
Default (DNEL calculator)
- AF for dose response relationship:
- 1
- Justification:
- Default (DNEL calculator)
- AF for differences in duration of exposure:
- 6
- Justification:
- Default (DNEL calculator)
- AF for interspecies differences (allometric scaling):
- 4
- Justification:
- Default (DNEL calculator)
- AF for other interspecies differences:
- 2.5
- Justification:
- Default (DNEL calculator)
- AF for intraspecies differences:
- 10
- Justification:
- Default (DNEL calculator)
- AF for the quality of the whole database:
- 1
- Justification:
- Default (DNEL calculator)
- AF for remaining uncertainties:
- 1
- Justification:
- no remaining uncertainties
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:
- DNEL (Derived No Effect Level)
- Value:
- 1.67 mg/kg bw/day
- Most sensitive endpoint:
- effect on fertility
- Route of original study:
- Oral
DNEL related information
- DNEL derivation method:
- ECHA REACH Guidance
- Overall assessment factor (AF):
- 600
- Dose descriptor starting point:
- NOAEL
- Value:
- 1 000 mg/kg bw/day
- Modified dose descriptor starting point:
- NOAEL
- Value:
- 1 000 mg/kg bw/day
- Explanation for the modification of the dose descriptor starting point:
Default (DNEL calculator)
- AF for dose response relationship:
- 1
- Justification:
- Default (DNEL calculator)
- AF for differences in duration of exposure:
- 6
- Justification:
- Default (DNEL calculator)
- AF for interspecies differences (allometric scaling):
- 4
- Justification:
- Default (DNEL calculator)
- AF for other interspecies differences:
- 2.5
- Justification:
- Default (DNEL calculator)
- AF for intraspecies differences:
- 10
- Justification:
- Default (DNEL calculator)
- AF for the quality of the whole database:
- 1
- Justification:
- Default (DNEL calculator)
- AF for remaining uncertainties:
- 1
- Justification:
- no remaining uncertainties
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
The principles of the DNEL calculation for the general population are the same as already described for workers. However, there are additional considerations or deviations for:
Modification of the starting point:
Bioavailability (absorption)
The oral absorption in rats and in humans is assumed to be the same since no information for oral absorption for target chemical in rats and in humans is available.
Respiratory volumes:
No differences in the respiratory volumes under normal conditions and by light activity in humans were taken into account. A default respiratory volume of 1.15 m³/kg bw for rats over 24h is considered for the conversion of the oral NOAEL into inhalation NOAEC for consumers, who are presumed to be continuously exposed to the substance, and have an assumed body weight of 70 kg.
Applying of assessment factors:
A higher assessment factor of 10 (instead of 5 for workers) for intraspecies variation/differences of human population was used.
Calculation of endpoint-specific DNEL for general population
Long-term exposure - systemic effects (oral)
The oral NOAEL of 1000 mg/kg bw was not modified for differences in absorption by oral route since no substance- and route specific information is available: Oral NOAEL rat = oral NOAEL human = 1000 mg/kg bw.
DNEL = 1000 mg/kg bw/(1 x 6 x 4 x 2.5 x 10 x 1 x 1) = 1.67 mg/kg bw.
Assessment factors are:1 – dose response (clear dose response), 6 – study duration (subacute to chronic), 4 – interspecies, allometric scaling, 2.5 – remaining interspecies differences, 10 – intraspecies (general population), 1 – quality of data base, 1 – remaining uncertainties (none remaining).
Long-term exposure - systemic effects (dermal)
The oral NOAEL of 1000 mg/kg bw was converted into the dermal NOAEL: Dermal NOAEL = oral NOAEL x (ABS oral-rat/ABS dermal-human) = 1000 mg/kg bw x (50%/10%) = 5000 mg/kg bw.
DNEL = 5000 mg/kg bw/(1 x 6 x 4 x 2.5 x 10 x 1 x 1) = 8.33 mg/kg bw.
Assessment factors are: 1 – dose response (clear dose response), 6 – study duration (subacute to chronic), 4 – interspecies, allometric scaling, 2.5 – remaining interspecies differences, 10 – intraspecies (general population), 1 – quality of data base, 1 – remaining uncertainties (none remaining).
Long-term exposure - systemic effects (inhalation)
The oral NOAEL of 1000 mg/kg bw was converted into the inhalation NOAEC:
Corrected inhalation NOAEC = oral rat NOAEL x (1/1.15 m³/kg bw/day) x (ABS oral-rat/ABS inhal-human), where 1.15 m³/kg bw is standard respiratory volume of rats during 24 h, ABS is absorption (values are the same as described for workers).
Corrected Inhalation NOAEC = 1000 mg/kg bw x (1/1.15 m³/kg/day) x (50%/10%) = 4347.8 mg/m³
DNEL = 4347.8 mg/m³/(1 x 6 x 1 x 2.5 x 10 x 1 x 1) = 28.99 mg/m³.
Assessment factors are:1 – dose response (clear dose response), 6 – study duration (subacute to chronic), 1 – interspecies, no allometric scaling required for oral to inhalation exposure, 2.5 – remaining interspecies differences, 10 – intraspecies (general population), 1 – quality of data base, 1 – remaining uncertainties (none remaining).
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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