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EC number: 924-669-1 | CAS number: -
- 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:
- 14.81 mg/m³
- Most sensitive endpoint:
- repeated dose toxicity
- Route of original study:
- Oral
DNEL related information
- DNEL derivation method:
- ECHA REACH Guidance
- Overall assessment factor (AF):
- 25
- Dose descriptor starting point:
- NOAEL
- Value:
- 300 mg/kg bw/day
- Modified dose descriptor starting point:
- NOAEC
- Value:
- 370.26 mg/m³
- Explanation for the modification of the dose descriptor starting point:
Standard respiratory volume, human (sRVhuman) for 8 h per person (70 kg): 6.7 m3
Standard respiratory volume of the rat (sRVrat) for 8 hours: 0.38 m3/kg bw
Worker respiratory volume (wRV) for 8 hours with light physical activity per person: 10 m3
Oral absorption of the rat/ inhalation absorption of humans (ABS oral-rat / ABS inh.-human): 1/2
Correction for difference between human and experimental exposure conditions: 7 d rat/5 d worker
Corrected NOAEC (inhalation) for workers:
NOAECcorr = NOAELoral x 1/0.38 m³/kg bw/day x 6.7 m³/10m³ x 7d/5d x ABSoral/ABSinh
NOAECcorr = 300 mg/kg bw/day x 1/0.38 m³/kg bw/day x 6.7 m³/10m³ x 7d/5d x 1/2NOAECcorr =370.26 mg/m3
- AF for dose response relationship:
- 1
- Justification:
- The dose response relationship is considered unremarkable, therefore no additional factor is used.
- AF for differences in duration of exposure:
- 2
- Justification:
- The standard assessment factor for time extrapolation from subchronic to chronic duration was used.
- AF for interspecies differences (allometric scaling):
- 1
- Justification:
- No allometric scalling is applied for inhalation as the inhalative data is standardized with reference to the respiratory rates. Respiratory rates depend directly on caloric demand, therefore inhalative study results are already extrapolated to humans on the basis of metabolic rate scaling (=allometric scaling).
- AF for other interspecies differences:
- 2.5
- Justification:
- Recommended AF for other interspecies differences.
- AF for intraspecies differences:
- 5
- Justification:
- The default value for the relatively homogenous group "worker" is used.
- AF for the quality of the whole database:
- 1
- Justification:
- The quality of the whole data base is considered to be sufficient and uncritical.
- AF for remaining uncertainties:
- 1
- Justification:
- The approach used for DNEL derivation is conservative. No further assessment factors are required.
Acute/short term exposure
- Hazard assessment conclusion:
- no hazard identified
- Most sensitive endpoint:
- acute toxicity
DNEL related information
Local effects
Long term exposure
- Hazard assessment conclusion:
- no hazard identified
- Most sensitive endpoint:
- skin irritation/corrosion
Acute/short term exposure
- Hazard assessment conclusion:
- no hazard identified
- Most sensitive endpoint:
- skin irritation/corrosion
DNEL related information
Workers - Hazard via dermal route
Systemic effects
Long term exposure
- Hazard assessment conclusion:
- DNEL (Derived No Effect Level)
- Value:
- 42 mg/kg bw/day
- Most sensitive endpoint:
- repeated dose toxicity
- Route of original study:
- Oral
DNEL related information
- DNEL derivation method:
- ECHA REACH Guidance
- Overall assessment factor (AF):
- 100
- Dose descriptor starting point:
- NOAEL
- Value:
- 300 mg/kg bw/day
- Modified dose descriptor starting point:
- NOAEL
- Value:
- 4 200 mg/kg bw/day
- Explanation for the modification of the dose descriptor starting point:
From physic-chemical properties of Reaction product of Hexamethylene diisocyanate, oligomers with Mercaptopropyl-trimethoxysilane a low dermal absorption is predicted because of its low water solubility, a molecular weight above 500 g/mol and an estimated log Pow value of 7.11. In cases were the molecular weight is above 500 and log Pow values outside the range of -1 to 4 are observed, a value of 10% skin absorption can be assumed.
Oral absorption of the rat/ dermal absorption of humans (ABS oral-rat / ABS derm-human): 1/1
Correction for difference between human and experimental exposure conditions: 7 d rat/5 d worker
Corrected NOAEL (dermal) for workers:
NOAELcorr = NOAELoral x 7d/5d x ABSoral/ABSderm
NOAELcorr = 300 mg/kg bw/day x 7d/5d x 1/0.1NOAELcorr = 4200 mg/kg bw/day
- AF for dose response relationship:
- 1
- Justification:
- The dose response relationship is considered unremarkable, therefore no additional factor is used.
- AF for differences in duration of exposure:
- 2
- Justification:
- The standard assessment factor for time extrapolation from subchronic to chronic duration was used.
- AF for interspecies differences (allometric scaling):
- 4
- Justification:
- The default allometric scaling factor for the differences between rats and humans is used.
- AF for other interspecies differences:
- 2.5
- Justification:
- Recommended AF for other interspecies differences.
- AF for intraspecies differences:
- 5
- Justification:
- The default value for the relatively homogenous group "worker" is used.
- AF for the quality of the whole database:
- 1
- Justification:
- The quality of the whole data base is considered to be sufficient and uncritical.
- AF for remaining uncertainties:
- 1
- Justification:
- The approach used for DNEL derivation is conservative. No further assessment factors are required.
Acute/short term exposure
- Hazard assessment conclusion:
- no hazard identified
- Most sensitive endpoint:
- acute toxicity
DNEL related information
Local effects
Long term exposure
- Hazard assessment conclusion:
- high hazard (no threshold derived)
- Most sensitive endpoint:
- sensitisation (skin)
Acute/short term exposure
- Hazard assessment conclusion:
- high hazard (no threshold derived)
- Most sensitive endpoint:
- sensitisation (skin)
Workers - Hazard for the eyes
Local effects
- Hazard assessment conclusion:
- no hazard identified
Additional information - workers
General
DNEL derivation for the test item is performed under consideration of the recommendations of ECHA, Guidance on information requirements and chemical safety assessment, Chapter R.8: Characterization of dose-response for human health (Version: 2.1, November 2012). In view of the data used for evaluation, the "quality of whole database factors" and "dose-response factors" are considered to amount each to a value of 1, and are thus not shown in the calculations presented below.
Inhalation
Long term, systemic DNEL – exposure via inhalation (workers)
Using a conservative approach, a worker DNEL (long-term inhalation exposure) is calculated. This worker long-term DNEL is considered to ensure an appropriate level of protection with regard to acute inhalation exposure (no high peaks of exposure expected).
No repeated dose inhalation toxicity study with the target substance is available. Therefore, it will be necessary to obtain a long-term DNEL by route-to-route extrapolation:
The combined repeated dose oral toxicity study OECD 422 is selected for DNEL derivation as it is the relevant repeated dose study performed in accordance to OECD guideline and GLP. In this study, the oral systemic NOAEL is 300 mg/kg bw/day. This NOAEL is used as PoD.
PoD: NOAEL = 300 mg/kg bw/day
Step 1: Modification of PoD into correct starting point:
Standard respiratory volume, human (sRVhuman) for 8 hours: 6.7 m3
Standard respiratory volume of the rat (sRVrat) for 8 hours: 0.38 m3/kg bw/d
Worker respiratory volume (wRV) for 8 hours with light physical activity: 10 m3
Oral absorption of the rat/ inhalation absorption of humans (ABS oral-rat / ABS inh-human): 50%/100 % (default)
Correction for difference between human and experimental exposure conditions: 7 d rat/5 d worker
Corrected NOAEC (inhalation) for workers:
= 300 mg/kg bw/day x 0.5 x 1/0.38 m3/kg bw/day x (6.7 m3/10 m3) x (7/5)
= 370.26 mg/m3
Step 2: Use of assessment factors
Intraspecies AF (workers): 5
Interspecies AF, remaining differences: 2.5
Exposure duration AF: 2 (default)
Remaining uncertainties AF: 1
Overall AF= 25
In conclusion, long term systemic inhalation DNEL, workers = 14.81 mg/m3
Acute, systemic DNEL- exposure via inhalation (workers)
No data for the classification and labelling of the test substance for acute inhalation toxicity is available. The substance is not classified for acute oral toxicity, therefore no adverse result for inhalation toxicity is expected (in accordance with "Guidance on information requirements and chemical safety assessment", chapter R8). Furthermore, due to the extremely low vapour pressure (3.93E-4 Pa at 20°C and 5.9E-4 Pa at 25°C) of Reaction product of Hexamethylene diisocyanate, oligomers with Mercaptopropyltrimethoxysilane, inhalation exposure is not considered as relevant. The substance is unlikely to be available as a vapor. As the substance is a liquid no generation of dust is assumed. Therefore, no DNEL was derived.
Long term & acute, local DNEL- exposure via inhalation (workers)
The substance is not classified for skin irritation/corrosion according to Regulation EC No 1272/2008 and in conclusion local mucosal irritation of the respiratory membranes is not expected.
Dermal
Long term, systemic DNEL- exposure via dermal route (workers)
No repeated dose dermal toxicity study with the target substance is available. Therefore, it will be necessary to obtain a long-term dermal DNEL by route-to-route extrapolation.
The combined repeated dose oral toxicity study OECD 422 is selected for DNEL derivation as it is the relevant repeated dose study performed in accordance to OECD guideline and GLP. In this study, the oral systemic NOAEL is 300 mg/kg bw/day. This NOAEL is used as PoD.
PoD: NOAEL = 300 mg/kg bw/day
Step 1: Modification of PoD into correct starting point:
Correction for difference between human and experimental exposure conditions: 7 d rat/5 d worker
Oral absorption of the rat / dermal absorption of humans (ABSoral-rat/ ABSdermal-human): 100%/10%
From physic-chemical properties of Reaction product of Hexamethylene diisocyanate, oligomers with Mercaptopropyl-trimethoxysilane a low dermal absorption is predicted because of its low water solubility, a molecular weight above 500 g/mol and an estimated log Pow value of 7.11. In cases were the molecular weight is above 500 and log Pow values outside the range of -1 to 4 are observed a value of 10% skin absorption can be assumed.
Corrected NOAEL (dermal) for workers:
= 300 mg/kg bw/day x (7/5) x (100%/10%)
= 4200 mg/kg bw/day
Step 2: Use of assessment factors
Interspecies AF, allometric scaling (rat to human): 4
Interspecies AF, remaining differences: 2.5
Intraspecies AF (worker): 5
Exposure duration AF: 2
Remaining uncertainties AF: 1
Overall AF= 100
In conclusion, long term systemic dermal DNEL, workers = 42 mg/kg bw/day
Acute, systemic DNEL- dermal exposure (workers)
The test material is not classified and labelled for acute dermal toxicity, according to Regulation (EC) No 1272/2008 (CLP). Thus, no DNEL is required.
Long term & acute, local DNEL- dermal exposure (workers)
Reaction product of Hexamethylene diisocyanate, oligomers with Mercaptopropyltrimethoxysilane is classified for skin sensitization Cat 1A. Therefore the substance is allocated to the high hazard band (according to "Guidance on Information Requirements and Chemical Safety Assessment Part E: Risk Characterisation", May 2016). A qualitative risk assessment is conducted.
Hazard to the eye-local effects (workers)
The test item is not classified for eye damage according to Regulation (EC) No 1272/2008 (CLP). Therefore, no hazard has been identified.
References
ECHA (2012). Guidance on information requirements and chemical safety assessment. Chapter R.8: Characterisation of dose [concentration]-response for human health. Version 2.1, November 2012
ECHA (2016). Guidance on information requirements and chemical safety assessment. Part E: Risk Characterisation, Version 3.0, May 2016
General Population - Hazard via inhalation route
Systemic effects
Long term exposure
- Hazard assessment conclusion:
- DNEL (Derived No Effect Level)
- Value:
- 2.61 mg/m³
- Most sensitive endpoint:
- repeated dose toxicity
- Route of original study:
- Oral
DNEL related information
- DNEL derivation method:
- ECHA REACH Guidance
- Overall assessment factor (AF):
- 50
- Dose descriptor starting point:
- NOAEL
- Value:
- 300 mg/kg bw/day
- Modified dose descriptor starting point:
- NOAEC
- Value:
- 130.43 mg/m³
- Explanation for the modification of the dose descriptor starting point:
Standard respiratory volume of the rat (sRVrat) for 24 hours: 1.15 m3/kg bw/day
Oral absorption of the rat/ inhalation absorption of humans (ABS oral-rat / ABS inh-human): 1/2 (default)
Corrected NOAEC (inhalation) for general population:
NOAECcorr = NOAELoral x 1/1.15 m³/kg bw/day x ABSoral/ABSinh
NOAECcorr = 300 mg/kg bw/day x 0.87 m³/kg bw/day x 1/2NOAECcorr = 130.43 mg/m3
- AF for dose response relationship:
- 1
- Justification:
- The dose response relationship is considered unremarkable, therefore no additional factor is used.
- AF for differences in duration of exposure:
- 2
- Justification:
- The standard assessment factor for time extrapolation from subchronic to chronic duration was used.
- AF for interspecies differences (allometric scaling):
- 1
- Justification:
- No allometric scalling is applied for inhalation as the inhalative data is standardized with reference to the respiratory rates. Respiratory rates depend directly on caloric demand, therefore inhalative study results are already extrapolated to humans on the basis of metabolic rate scaling (=allometric scaling).
- AF for other interspecies differences:
- 2.5
- Justification:
- Recommended AF for other interspecies differences.
- AF for intraspecies differences:
- 10
- Justification:
- The default value for the relatively homogenous group "general population" is used.
- AF for the quality of the whole database:
- 1
- Justification:
- The quality of the whole data base is considered to be sufficient and uncritical.
- AF for remaining uncertainties:
- 1
- Justification:
- The approach used for DNEL derivation is conservative. No further assessment factors are required.
Acute/short term exposure
- Hazard assessment conclusion:
- no hazard identified
DNEL related information
Local effects
Long term exposure
- Hazard assessment conclusion:
- no hazard identified
- Most sensitive endpoint:
- skin irritation/corrosion
Acute/short term exposure
- Hazard assessment conclusion:
- no hazard identified
- Most sensitive endpoint:
- skin irritation/corrosion
DNEL related information
General Population - Hazard via dermal route
Systemic effects
Long term exposure
- Hazard assessment conclusion:
- DNEL (Derived No Effect Level)
- Value:
- 15 mg/kg bw/day
- Most sensitive endpoint:
- repeated dose toxicity
- Route of original study:
- Oral
DNEL related information
- DNEL derivation method:
- ECHA REACH Guidance
- Overall assessment factor (AF):
- 200
- Dose descriptor starting point:
- NOAEL
- Value:
- 300 mg/kg bw/day
- Modified dose descriptor starting point:
- NOAEL
- Value:
- 3 000 mg/kg bw/day
- Explanation for the modification of the dose descriptor starting point:
From physic-chemical properties of Reaction product of Hexamethylene diisocyanate, oligomers with Mercaptopropyl-trimethoxysilane a low dermal absorption is predicted because of its low water solubility, a molecular weight above 500 g/mol and an estimated log Pow value of 7.11. In cases were the molecular weight is above 500 and log Pow values outside the range of -1 to 4 are observed, a value of 10% skin absorption can be assumed.
Oral absorption of the rat/ dermal absorption of humans (ABS oral-rat / ABS derm-human): 1/0.1
Corrected NOAEL (dermal) for general population:
NOAELcorr = NOAELoral x ABSoral/ABSderm
NOAELcorr = 300 mg/kg bw/day x 1/0.1NOAELcorr = 3000 mg/kg bw/day
- AF for dose response relationship:
- 1
- Justification:
- The dose response relationship is considered unremarkable, therefore no additional factor is used.
- AF for differences in duration of exposure:
- 2
- Justification:
- The standard assessment factor for time extrapolation from subchronic to chronic duration was used.
- AF for interspecies differences (allometric scaling):
- 4
- Justification:
- The default allometric scaling factor for the differences between rats and humans is used.
- AF for other interspecies differences:
- 2.5
- Justification:
- Recommended AF for other interspecies differences.
- AF for intraspecies differences:
- 10
- Justification:
- The default value for the relatively homogenous group "general population" is used.
- AF for the quality of the whole database:
- 1
- Justification:
- The quality of the whole data base is considered to be sufficient and uncritical.
- AF for remaining uncertainties:
- 1
- Justification:
- The approach used for DNEL derivation is conservative. No further assessment factors are required.
Acute/short term exposure
- Hazard assessment conclusion:
- no hazard identified
- Most sensitive endpoint:
- acute toxicity
DNEL related information
Local effects
Long term exposure
- Hazard assessment conclusion:
- high hazard (no threshold derived)
- Most sensitive endpoint:
- sensitisation (skin)
Acute/short term exposure
- Hazard assessment conclusion:
- high hazard (no threshold derived)
- Most sensitive endpoint:
- sensitisation (skin)
General Population - Hazard via oral route
Systemic effects
Long term exposure
- Hazard assessment conclusion:
- DNEL (Derived No Effect Level)
- Value:
- 1.5 mg/kg bw/day
- Most sensitive endpoint:
- repeated dose toxicity
- Route of original study:
- Oral
DNEL related information
- DNEL derivation method:
- ECHA REACH Guidance
- Overall assessment factor (AF):
- 200
- Dose descriptor starting point:
- NOAEL
- Value:
- 300 mg/kg bw/day
- Modified dose descriptor starting point:
- NOAEL
- Value:
- 300 mg/kg bw/day
- Explanation for the modification of the dose descriptor starting point:
No route-to-route extrapolation was performed since the original application route for this study was oral.
- AF for dose response relationship:
- 1
- Justification:
- The dose response relationship is considered unremarkable, therefore no additional factor is used.
- AF for differences in duration of exposure:
- 2
- Justification:
- The standard assessment factor for time extrapolation from subchronic to chronic duration was used.
- AF for interspecies differences (allometric scaling):
- 4
- Justification:
- The default allometric scaling factor for the differences between rats and humans is used.
- AF for other interspecies differences:
- 2.5
- Justification:
- Recommended AF for other interspecies differences.
- AF for intraspecies differences:
- 10
- Justification:
- The default value for the relatively homogenous group "general population" is used.
- AF for the quality of the whole database:
- 1
- Justification:
- The quality of the whole data base is considered to be sufficient and uncritical.
- AF for remaining uncertainties:
- 1
- Justification:
- The approach used for DNEL derivation is conservative. No further assessment factors are required.
Acute/short term exposure
- Hazard assessment conclusion:
- no hazard identified
- Most sensitive endpoint:
- acute toxicity
DNEL related information
General Population - Hazard for the eyes
Local effects
- Hazard assessment conclusion:
- no hazard identified
Additional information - General Population
General
DNEL derivation for the test item is performed under consideration of the recommendations of ECHA, Guidance on information requirements and chemical safety assessment, Chapter R.8: Characterization of dose-response for human health (Version: 2.1, November 2012). In view of the data used for evaluation, the "quality of whole database factors" and "dose-response factors" are considered to amount each to a value of 1, and are thus not shown in the calculations presented below.
Inhalation
Long term, systemic DNEL – exposure via inhalation (general population)
No repeated dose inhalation toxicity study with the target substance is available. Therefore, it will be necessary to obtain a long-term DNEL by route-to-route extrapolation:
The combined repeated dose oral toxicity study OECD 422 is selected for DNEL derivation as it is the relevant repeated dose study performed in accordance to OECD guideline and GLP. In this study, the oral systemic NOAEL is 300 mg/kg bw/day. This NOAEL is used as PoD.
PoD: NOAEL = 300 mg/kg bw/day
Step 1: Modification of PoD into correct starting point:
Standard respiratory volume of the rat (sRVrat) for 24 hours: 1.15 m3/kg bw
Oral absorption of the rat/ inhalation absorption of humans (ABS oral-rat / ABS inh-human):50%/100 % (default)
Corrected NOAEC (inhalation) for general population:
= 300 mg/kg bw/day x 0.5 x 1/1.15 m3/kg bw/day
= 130.43 mg/m3
Step 2: Use of assessment factors
Intraspecies AF (General population): 10
Interspecies AF, remaining differences: 2.5
Dose response relationship AF: 1
Exposure duration AF: 2
Remaining uncertainties AF: 1
Overall AF: 50
In conclusion, long term systemic inhalation DNEL, general population = 2.61 mg/m3
Acute, systemic DNEL- exposure via inhalation (general population)
No data for the classification and labelling of the test substance for acute inhalation toxicity is available. The substance is not classified for acute oral toxicity, therefore no adverse result for inhalation toxicity is expected (in accordance with "Guidance on information requirements and chemical safety assessment", chapter R8). Furthermore, due to the extremely low vapour pressure (3.93E-4 Pa at 20°C and 5.9E-4 Pa at 25°C) of Reaction product of Hexamethylene diisocyanate, oligomers with Mercaptopropyltrimethoxysilane, inhalation exposure is not considered as relevant. The substance is unlikely to be available as a vapor. As the substance is a liquid no generation of dust is assumed. Therefore, no DNEL was derived.
Long term, local DNEL- exposure via inhalation (general population)
The substance is not classified for skin irritation/corrosion according to Regulation EC No 1272/2008 and in conclusion local mucosal irritation of the respiratory membranes is not expected.
Dermal
Long term, systemic DNEL- exposure via dermal route (general population)
No repeated dose dermal toxicity study with the target substance is available. Therefore, it will be necessary to obtain a long-term dermal DNEL by route-to-route extrapolation.
The combined repeated dose oral toxicity study OECD 422 is selected for DNEL derivation as it is the relevant repeated dose study performed in accordance to OECD guideline and GLP. In this study, the oral systemic NOAEL is 300 mg/kg bw/day. This NOAEL is used as PoD.
PoD: NOAEL = 300 mg/kg bw/day
Step 1: Modification of PoD into correct starting point:
Correction for difference between human and experimental exposure conditions: 7 d rat, 24 h/7 d, 24h general population
Oral absorption of the rat / dermal absorption of humans (ABSoral-rat/ ABSdermal-human): 100%/10%
From physic-chemical properties of Reaction product of Hexamethylene diisocyanate, oligomers with Mercaptopropyl-trimethoxysilane a low dermal absorption is predicted because of its low water solubility, a molecular weight above 500 g/mol and an estimated log Pow value of 7.11. In cases were the molecular weight is above 500 and log Pow values outside the range of -1 to 4 are observed a value of 10% skin absorption can be assumed.
Corrected NOAEL (dermal) for general population:
= 300 mg/kg bw/day x (100%/10%) x (7/7)
= 3000 mg/kg bw/day
Step 2: Use of assessment factors
Interspecies AF, allometric scaling (rat to human): 4
Interspecies AF, remaining differences: 2.5
Intraspecies AF (general population): 10
Dose-response relationship AF: 1
Exposure duration AF: 2
Remaining uncertainties AF: 1
Overall AF: 200
In conclusion, long term systemic dermal DNEL, general population = 15 mg/kg bw/day
Acute, systemic DNEL- dermal exposure (general population)
The test material is not classified and labelled for acute dermal toxicity, according to Regulation (EC) No 1272/2008 (CLP). Thus, no DNEL is required.
Long term & acute, local DNEL- dermal exposure (general population)
Reaction product of Hexamethylene diisocyanate, oligomers with Mercaptopropyltrimethoxysilane is classified for skin sensitization Cat 1A. Therefore the substance is allocated to the high hazard band (according to "Guidance on Information Requirements and Chemical Safety Assessment Part E: Risk Characterisation", May 2016). A qualitative risk assessment is conducted.
Oral
Long term, systemic DNEL- exposure by oral route (general population)
The combined repeated dose oral toxicity study OECD 422 is selected for DNEL derivation as it is the relevant repeated dose study performed in accordance to OECD guideline and GLP. In this study, the oral systemic NOAEL is 300 mg/kg bw/day. This NOAEL is used as PoD.
PoD: NOAEL = 300 mg/kg bw/day
Step 1: Use of assessment factors
Interspecies AF, allometric scaling (rat to human): 4
Interspecies AF, remaining differences: 2.5
Interspecies AF, remaining differences: Interspecies differences are fully covered by the allometric scaling
Intraspecies AF (general population): 10
Dose-response relationship AF: 1
Exposure duration AF: 2
Remaining uncertainties AF: 1
Overall AF: 200
In conclusion, long term systemic oral DNEL, general population= 1.5 mg/kg bw/day
Acute, systemic DNEL- exposure by oral route (general population)
According to ECHA Guidance on information requirements and chemical safety, Chapter R.8, Appendix R. 8-8, „a DNEL for acute toxicity should be derived if an acute toxicity hazard (leading to C&L) has been identified. The substance has low acute dermal toxicity with the LD50 of >2000 mg/kg. Therefore, the DNEL is not required.
Hazard to the eye-local effects (general population)
The test item is not classified for eye damage according to Regulation (EC) No 1272/2008 (CLP).
References
ECHA (2012). Guidance on information requirements and chemical safety assessment. Chapter R.8:
Characterization of dose [concentration]-response for human health. Version 2.1, November 2012
ECHA (2016). Guidance on information requirements and chemical safety assessment. Part E: Risk Characterization, Version 3.0, May 2016
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.
Reproduction or further distribution of this information may be subject to copyright protection. Use of the information without obtaining the permission from the owner(s) of the respective information might violate the rights of the owner.