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EC number: 701-029-8 | 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
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Vapour pressure
Administrative data
Link to relevant study record(s)
Description of key information
All MDI substances have extremely low vapour pressures at room temperature (<0.01 Pa). Only special laboratories with highest precision could apply the mass-loss Knudsen effusion method for MDI substances at elevated temperatures from 30 to 90°C in order to extrapolate to room temperature. Due to this fact, measurements are difficult to perform and only the most reliable will be taken into account for assessment.
Substances of the ‘Monomeric MDI’ subgroup (4,4’-MDI, 2,4’-MDI, 2,2’-MDI and MDI Mixed Isomers) have the highest vapour pressure, ranging from 0.7 to 8.05 mPa at 20°C. All modified MDI substances of the subgroups ‘Oligomeric MDI’, ‘MDI reaction products with glycols’ and ‘MDI condensation products’ have lower values compared to the basic monomers they are made from.
The overall content of monomeric MDI isomers in all substances and the ratio of 2,4’-MDI and 4,4’-MDI are the main driver of air exposure (Gerbig and Jamin, 2018; Chakrabarti 1989) within the MDI category. The higher molecular weight constituents, i.e. MDI oligomers, condensation adducts or glycol adducts, all have much higher molecular weight and therefore much lower vapour pressure. These higher molecular weight constituents do not contribute to the overall vapour pressure of the MDI substances. Theoretical vapour pressure calculations support this hypothesis (see Chapter 1.3.2.2 of the Category Justification Document and supporting studies of Sadler 2019).
Chakrabarti (1989) used the mass-loss Knudsen effusion method which is the most applicable method for measuring the vapour pressure of the MDI substances and generated a huge data set for some MDI substances. This study is therefore rated with a Klimisch score of 1. A new study was performed (Gerbig and Jamin, 2018) using the same mass-loss Knudsen effusion method which is rated with a Klimisch score of 2 but with a smaller data set per substance. Therefore, the Chakrabarti (1989) study is chosen as KEY and the Gerbig and Jamin, 2018 study as support for 4,4’-MDI. Both studies match in their results. A graph in the additional information illustrates the findings of both studies. The Chakrabarti formular fits also the newer results of Gerbig et al. 2018.
As a read-across Gerbig and Jarmin (2018) and the respective mesaurement of BASF in 2016 of the MDI mixed isomer vapour pressure is used as key study for MDI mixed isomer/1,3-BD/TPG/PG as a worst-case approach (see also category justification document in Appendix 28 IUCLID section 13), since the substance is produced using MDI mixed isomer as starting material and as descirbed before the other constituents all have much higher molecular weight and do not contribute to the overall vapour pressure of the substance.
Therefore, the vapour pressure according to the study design of OECD Guideline 104 (Vapour pressure curve) in 2016 using the effusion method in a Knudsen cell, which was extrapolated from the regression equation of MDI mixed isomer, is:
Vapour pressure at 20°C: 0.00092 Pa
Key value for chemical safety assessment
- Vapour pressure:
- 0.001 Pa
- at the temperature of:
- 20 °C
Additional information
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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