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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.
The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.
Diss Factsheets
Use of this information is subject to copyright laws and may require the permission of the owner of the information, as described in the ECHA Legal Notice.
EC number: 448-050-6 | CAS number: 444065-11-6
- 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
![](https://echa.europa.eu/o/diss-blank-theme/images/factsheets/A-REACH/factsheet/print_toxicological-information.png)
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:
- 23.51 mg/m³
- Most sensitive endpoint:
- developmental toxicity / teratogenicity
- Route of original study:
- Oral
DNEL related information
- DNEL derivation method:
- ECHA REACH Guidance
- Overall assessment factor (AF):
- 75
- Modified dose descriptor starting point:
- NOAEC
- Value:
- 1 763 mg/m³
- Explanation for the modification of the dose descriptor starting point:
- Convert oral NOAEL to inhalation NOAEC: 1000 mg/kg/day x [1/0.38 x 1/1 x 6.7/10] = 1763 mg/m3
- AF for dose response relationship:
- 1
- Justification:
- No adverse effects observed in repeat dose, reproductive toxicity studies, or genetox
- AF for differences in duration of exposure:
- 6
- Justification:
- Default factor for subacute to chronic study extrapolation
- AF for interspecies differences (allometric scaling):
- 1
- Justification:
- Already taken into account during the correction of starting point
- AF for other interspecies differences:
- 2.5
- Justification:
- Default factor for remaining toxicodynamic differences
- AF for intraspecies differences:
- 5
- Justification:
- Default factor for workers
- AF for the quality of the whole database:
- 1
- Justification:
- Based on appropriate testing for tonnage, no adverse effects observed in repeat dose, reproductive toxicity studies, or genetox
- 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:
- 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
Workers - Hazard for the eyes
Local effects
- Hazard assessment conclusion:
- no hazard identified
Additional information - workers
2-6-di-tert-butyl-4-methylcyclohexyl 5-[bis(2-ethoxy-2-oxoethyl)carbamoyl]oxy-2-(4-tert-butylphenyl)-6-cyano-1H-pyrrolo[1,2-b][1,2,4]triazole-7-carboxylate (529A coupler, UC-141), is not acutely toxic in respect to the oral and dermal route, with LD50 values greater than 2000 mg/kg bw. 529A coupler is not acutely toxic following inhalation exposure with an LC50 values greater than 5 mg/L. No local effects following inhalation are expected to occur as 529A coupler is neither corrosive nor irritating to the skin, and was not irritating to the eye in an in vivo study. In addition, no sensitising potential was identified in a guinea pig maximisation test. Therefore, acute DNELs for systemic effects, or long-term or acute DNELs for local effects are not possible to define. It would also be unnecessary to set acute systemic DNELs for inhalation because Risk Management Measures are implemented in working places to assure that exposure, if any, remains below the long-term inhalation DNEL.
Based on results of in vitro studies 529A coupler is not considered to possess any genotoxic potential.
In an OECD 421 reproduction/developmental toxicity screen (Török-Bathó, 2014, gavage), and an OECD 407 repeat dose 28-day oral toxicity study (Hooiveld, 2004, gavage), no effects were observed at any time point up to the limit dose (1000 mg/kg bw/day). These studies were used as the starting point for DNEL setting.
Considering the extreme log Pow value (>11), the large molecular weight (>700) and that this material is an insoluble solid, virtually no oral absorption is anticipated (no toxicity was elicited in repeat dose oral gavage studies upto the limit dose). By extension, no measurable dermal absorption of this material is anticipated (In an OECD 402 acute dermal toxicity (Hooiveld, 2004, tested up to 2000 mg/kg bw), there were no effects observed that would give any indication that any dermal absorption had taken place) and dermal absorption is anticipated to be 0%. Therefore, a long-term dermal DNEL for systemic effects is not necessary as the material will not enter the body through the dermal route to any toxicologically significant levels.
A safety factor of 1 has been applied for the quality of the database based on appropriate testing for the tonnage and that no adverse effects were observed in the repeat dose, reproductive toxicity studies, or genetic toxicity studies.
General Population - Hazard via inhalation route
Systemic effects
Long term exposure
- Hazard assessment conclusion:
- DNEL (Derived No Effect Level)
- Value:
- 5.8 mg/m³
- Most sensitive endpoint:
- developmental toxicity / teratogenicity
- Route of original study:
- Oral
DNEL related information
- DNEL derivation method:
- ECHA REACH Guidance
- Overall assessment factor (AF):
- 150
- Modified dose descriptor starting point:
- NOAEC
- Value:
- 870 mg/m³
- Explanation for the modification of the dose descriptor starting point:
- Convert oral NOAEL to inhalation NOAEC: 1000 mg/kg/day x [1/1.15 x 1/1] = 870 mg/m3
- AF for dose response relationship:
- 1
- Justification:
- No adverse effects observed in repeat dose, reproductive toxicity studies, or genetox
- AF for differences in duration of exposure:
- 6
- Justification:
- Default factor for subacute to chronic study extrapolation
- AF for interspecies differences (allometric scaling):
- 1
- Justification:
- Already taken into account during the correction of starting point
- AF for other interspecies differences:
- 2.5
- Justification:
- Default factor for remaining toxicodynamic differences
- AF for intraspecies differences:
- 10
- Justification:
- Default factor for general population
- AF for the quality of the whole database:
- 1
- Justification:
- Based on appropriate testing for tonnage, no adverse effects observed in repeat dose, reproductive toxicity studies, or genetox
- 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
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:
- DNEL (Derived No Effect Level)
- Value:
- 1.67 mg/kg bw/day
- Most sensitive endpoint:
- developmental toxicity / teratogenicity
- Route of original study:
- Oral
DNEL related information
- DNEL derivation method:
- ECHA REACH Guidance
- Overall assessment factor (AF):
- 600
- Modified dose descriptor starting point:
- NOAEL
- Value:
- 1 000 mg/kg bw/day
- Explanation for the modification of the dose descriptor starting point:
- NOAEL: 1000 mg/kg bw/day
- AF for dose response relationship:
- 1
- Justification:
- No adverse effects observed in repeat dose, reproductive toxicity studies, or genetox
- AF for differences in duration of exposure:
- 6
- Justification:
- Default factor for subacute to chronic study extrapolation
- AF for interspecies differences (allometric scaling):
- 4
- Justification:
- Default factor for extrapolating toxicokinetics from rat to human
- AF for other interspecies differences:
- 2.5
- Justification:
- Default factor for remaining toxicodynamic differences
- AF for intraspecies differences:
- 10
- Justification:
- Default factor for general population
- AF for the quality of the whole database:
- 1
- Justification:
- Based on appropriate testing for tonnage, no adverse effects observed in repeat dose, reproductive toxicity studies, or genetox
- 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
2-6-di-tert-butyl-4-methylcyclohexyl 5-[bis(2-ethoxy-2-oxoethyl)carbamoyl]oxy-2-(4-tert-butylphenyl)-6-cyano-1H-pyrrolo[1,2-b][1,2,4]triazole-7-carboxylate (529A coupler, UC-141), is not acutely toxic in respect to the oral and dermal route, with LD50 values greater than 2000 mg/kg bw. 529A coupler is not acutely toxic following inhalation exposure with an LC50 values greater than 5 mg/L. No local effects following inhalation are expected to occur as 529A coupler is neither corrosive nor irritating to the skin, and was not irritating to the eye in an in vivo study. In addition, no sensitising potential was identified in a guinea pig maximisation test. Therefore, acute DNELs for systemic effects or long-term or acute DNELs for local effects are not possible to define.
Based on results of in vitro studies 529A coupler is not considered to possess any genotoxic potential.
In an OECD 421 reproduction/developmental toxicity screen (Török-Bathó, 2014, gavage), and an OECD 407 repeat dose 28-day oral toxicity study (Hooiveld, 2004, gavage), no effects were observed at any time point up to the limit dose (1000 mg/kg bw/day. These studies were used as the starting point for DNEL setting.
Considering the extreme log Pow value (>11), the large molecular weight and that this material is an insoluble solid, virtually no oral absorption is anticipated (no toxicity was elicited in repeat dose oral gavage studies upto the limit dose). By extension, no measurable dermal absorption of this material is anticipated. In an OECD 402 acute dermal toxicity (Hooiveld, 2004, tested up to 2000 mg/kg bw) there were no effects observed that would give any indication that any dermal absorption had taken place) and dermal absorption is anticipated to be 0%. Therefore, a long-term dermal DNEL for systemic effects is not necessary as the material will not enter the body through the dermal route to any toxicologically significant levels.
A safety factor of 1 has been applied for the quality of the database based on appropriate testing for the tonnage and that no adverse effects were observed in the repeat dose, reproductive toxicity studies, or genetic toxicity studies.
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.
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