Registration Dossier
Registration Dossier
Data platform availability banner - registered substances factsheets
Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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: 212-344-0 | CAS number: 793-24-8
- 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
Hydrolysis
A high number of hydrolysis tests is available for the different PPDs, but up to now no test has been performed according to OECD 111.
However, a full OECD 111 study is available for 6QDI (N-(1,3-dimethylbutyl)-N'-(phenyl)-1,4-benzoquinonediimine, CAS No. 52870-46-9) which is the oxidized form of 6PPD. As the PPDs are sensitive to oxidation, 6QDI is regarded as the primary oxidation product of 6PPD which is expected also to be formed under hydrolytic conditions in the presence of oxygen. For this reason, this substance has been included in the read-across approach.
In the Table below, the key values for the hydrolysis half-lives and the information from all available hydrolysis tests concerning the occurrence of hydrolysis products are summarized:
Table: Results of hydrolysis tests
|
6PPD |
6QDI |
7PPD |
77PD |
44PD |
Half-life (h) |
pH7: 8 |
pH4: 19 pH7: 4.7 pH9: 4.3 |
pH7: 5.15 |
pH7: 3.4 |
pH4: 200 pH7: 5 pH9: 1.5 |
Hydrolysis products identified |
4-Hydroxy-diphenylamine
|
4-Hydroxy-diphenylamine
p-Benzoquinone p-Hydroquinone Aniline |
4-Hydroxy-diphenylamine
N-Phenyl-p-benzoquinone mono-imine |
N-1,4 dimethylpentyl-p-phenol
p-Benzoquinone |
4,4-Quinone-diimine (44QDI) N-1,4 dimethyl- p-Benzoquinone pentylamine |
The half-lives of the PPDs at the environmental relevant pH of 7 are in the same range (3.4 to 8 hours). The primary step of the hydrolysis is considered to occur rapidly.
Considering all information given in the various reports, the hydrolysis pathway of all PPDs follows the same pattern. The picture of the hydrolysis scheme is outlined in the read-across justification document attached to the IUCLID in chapter 13 (Allmendinger 2016).
The first step of hydrolysisis the cleavage of the alkyl chain yielding the phenolic compound (e.g. 4-hydroxydiphenylamine) and the alkylamine (e.g. 1,3 -dimethylbutylamine). It should be noted that the alkylamine has never been monitored in hydrolysis studies probably due to problems in chromatography. Only in the ready biodegradation test (MITI 1995) the alkylamine could be determined, but only after derivatisation.
In parallel, a further primary hydrolysis product is formed: the quinone-monoimine. It is not quite clear whether the formation occurs via hydrolysis of the oxidized PPD (e.g. 6QDI) or via oxidation of the phenolic compound (e.g. 4 -hydroxydiphenylamine). It should be noted that the formation of the quinone-monoimine can be explained in case of 6PPD as well as in case of 7PPD (R1=phenyl) as the formation of the substance is preferred by mesomeric stabilisation. In case of 77PD (R1=1,4-dimethylpentyl) the formation of the quinone-monoimine was not observed as no mesomeric-stabilised aromatic system can be formed.
The second step of hydrolysis is the cleavage of the second amino group which is linked to R1=phenyl (in case of 6PPD, 7PPD) The secondary hydrolysis products are p-benzoquinone and p-hydroquinone as well as the respective amine. In case of phenylenediamines linked to phenyl groups (6PPD, 7PPD), the amine formed is aniline.
As explained above, the formation of the primary hydrolysis products occurs rapidly (half-life 3.4 to 8 hours). The half-life of the secondary hydrolysis products has not been described in detail. However, after having assessed the available information one can conclude that the primary hydrolysis products of 6PPD and 7PPD, namely 4-hydroxydiphenyl-amine and benzoquinone-monoimine, are rather stable, and the secondary hydrolysis reaction occurs more slowly.
The secondary hydrolysis productsp-benzoquinone, p-hydroquinone and the relevant amines are known to be readily biodegradable.
Photolysis
6PPD degrades rapidly by indirect photolysis and by hydrolysis.
In the atmosphere a half-life of 1.7 hours for N-(1,3-dimethylbutyl)-N'-phenylbenzene-1,4-diamine (6PPD) is estimated due to reaction with photochemically produced hydroxyl radicals, considering an OH-concentration of 500,000 radicals/cm³ as a 24-h average (Currenta, 2009).
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.