Registration Dossier
Registration Dossier
Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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.
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: 201-143-3 | CAS number: 78-79-5
Toxicological Summary
Administrative data
Workers - Hazard via inhalation route
Systemic effects
Long term exposure
- Hazard assessment conclusion:
- DNEL (Derived No Effect Level)
- Value:
- 8.4 mg/m³
DNEL related information
- DNEL derivation method:
- other: based on MAK value
- Overall assessment factor (AF):
- 1
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:
- DNEL (Derived No Effect Level)
- Value:
- 40 mg/kg bw/day
DNEL related information
- DNEL derivation method:
- other: based on MAK value
- Overall assessment factor (AF):
- 1
- Modified dose descriptor starting point:
- other:
- Value:
- 40 mg/kg bw/day
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
The MAK derived a workplace exposure limit (MAK-Wert) of 8.4mg/m³ based on the external exposure concentration, over 8h/day for 40 years, that would not increase baseline blood concentrations (area under the curve) above that arising from endogenous formation of isoprene. Such a concentration is, therefore, considered to offer no appreciable cancer risk (MAK, 2009).
Because the MAK value is based on the endogenous formation of isoprene, assessment factors are not considered appropriate (overall AF=1).
General Population - Hazard via inhalation route
Systemic effects
Long term exposure
- Hazard assessment conclusion:
- DNEL (Derived No Effect Level)
- Value:
- 2 mg/m³
DNEL related information
- DNEL derivation method:
- other: based on MAK value
- Overall assessment factor (AF):
- 1
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:
- DNEL (Derived No Effect Level)
- Value:
- 9.5 mg/kg bw/day
DNEL related information
- DNEL derivation method:
- other: based on MAK value
- Overall assessment factor (AF):
- 1
- Modified dose descriptor starting point:
- other:
- Value:
- 9.5 mg/kg bw/day
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:
- 0.2 mg/kg bw/day
DNEL related information
- DNEL derivation method:
- other: based on MAK value
- Overall assessment factor (AF):
- 1
- Modified dose descriptor starting point:
- other:
- Value:
- 0.2 mg/kg bw/day
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
The MAK derived a workplace exposure limit (MAK-Wert) of 8.4mg/m³ based on the external exposure concentration, over 8h/day for 40 years, that would not increase baseline blood concentrations (area under the curve) above that arising from endogenous formation of isoprene. Such a concentration is, therefore, considered to offer no appreciable cancer risk (MAK, 2009). This value is converted, as approprirate, to account for differences in exposure patterns between workers and the general population.
Because the MAK value is based on the endogenous formation of isoprene, assessment factors are not considered appropriate (overall AF=1).
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.
