Registration Dossier
Registration Dossier
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: 204-617-8 | CAS number: 123-31-9
- 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
Description of key information
Additional information
- During the manufacture, industrial uses, professional use and consumer use of hydroquinone, there is no intentional release of hydroquinone to the soil. Therefore, direct exposure of the soil compartment is unlikely.
- Indirect exposure of the soil compartment via sludge application to land is considered as very limited because hydroquinone is readily biodegradable and has a low adsorptive potential (log Koc = 50 L/kg).
- Indirect exposure of the soil compartment via aerial deposition is considered as very limited because hydroquinone has a very low volatility (Vapour pressure = 0.0032 Pa at 25°C and Henry’s Law constant = 4.7927 E-06 Pa-m³/mol at 25°C).
- Hydroquinone is not persistent and has a low potential to partition to soil. Therefore, it is not of particular concern for soil compartment.
- The chemical safety assessment performed with combined EU tonnage volumes and the equilibrium partitioning method results in RCR values for agricultural soil below 0.2. These results do not indicate the need to investigate further the effects to terrestrial organisms.
- Normally, micro-organism testing alone would not be considered sufficient for the derivation of the PNECsoil, but can be considered as part of a Weight-of-Evidence approach. If an assessment factor of 1000 is applied to the EC50 obtained in the soil micro-organisms toxicity study, a PNECsoil of 60.1 µg/kg soil (dw) is derived. This PNECsoil is higher than the PNEC derived by the Equilibrium partitioning method, i.e. 0.64 µg/kg soil (dw). Therefore there is no indication of risk from the available soil toxicity test.
In accordance with the decision on substance evaluation pursuant to article 46(1) of Regulation (EC) No 1907/2006 for hydroquinone, a soil micro-organisms toxicity study has been performed according to the OECD TG 216 and under GLP. The 28d EC10 and EC50 were estimated at 19.5 and 60.1 mg hydroquinone/kg dry soil, respectively. The NOEC was determined as 10.0 mg hydroquinone/kg dry soil.
Concerning the other terrestrial endpoints, in accordance with column 2 of REACH Annexes IX and X, testing on toxicity to terrestrial organisms does not need to be conducted because of the following conclusions:
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.
