Registration Dossier
Registration Dossier
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EC number: 204-070-5 | CAS number: 115-19-5
Toxicological Summary
Administrative data
Workers - Hazard via inhalation route
Systemic effects
Long term exposure
- Hazard assessment conclusion:
- DNEL (Derived No Effect Level)
- Value:
- 3.2 mg/m³
- Most sensitive endpoint:
- repeated dose toxicity
- Route of original study:
- Oral
DNEL related information
- DNEL derivation method:
- ECHA REACH Guidance
- Overall assessment factor (AF):
- 25
- Dose descriptor starting point:
- NOAEL
- Value:
- 45 mg/kg bw/day
- Modified dose descriptor starting point:
- NOAEC
- Value:
- 78.8 mg/m³
- Explanation for the modification of the dose descriptor starting point:
The administration of 2-methylbut-3-yn-2-ol by gavage to male and female Wistar rats for 3 months caused signs of systemic toxicity manifested next to others on kidneys of male animals at dose levels beyond 45 mg/kg bw/d. Increased absolute and relative kidney weights of males were regarded as treatment-related as there as both a macroscopic (enlarged, discoloration) and a histological correlate (increased eosinophilic droplets graded moderate to severe). Additionally, increased basophilic tubules and tubular casts were seen in these test groups. Findings in the kidney of male animals were assessed as treatment-related and adverse. Therefore, the starting point for DNEL derivation was set to 45 mg/kg bw/d.
- AF for dose response relationship:
- 1
- Justification:
- default value according to ECHA REACH Guidance: normal dose response relationship
- AF for differences in duration of exposure:
- 2
- Justification:
- default value according to ECHA REACH Guidance: extrapolation from subchronic to chronic exposure
- AF for interspecies differences (allometric scaling):
- 1
- Justification:
- default value according to ECHA REACH Guidance: allometric scaling is not applied, because the ventilation rate directly depends on the basal metabolic rate
- AF for other interspecies differences:
- 1
- Justification:
- default value according to ECHA REACH Guidance: no further interspecies differences expected
- AF for intraspecies differences:
- 5
- Justification:
- default value according to ECHA REACH Guidance
- AF for the quality of the whole database:
- 1
- Justification:
- default value according to ECHA REACH Guidance: modern guideline study
- AF for remaining uncertainties:
- 2.5
- Justification:
- default value according to ECHA REACH Guidance
Acute/short term exposure
- Hazard assessment conclusion:
- low hazard (no threshold derived)
DNEL related information
Local effects
Long term exposure
- Hazard assessment conclusion:
- DNEL (Derived No Effect Level)
- Value:
- 3.2 mg/m³
Acute/short term exposure
- Hazard assessment conclusion:
- DNEL (Derived No Effect Level)
- Value:
- 6.4 mg/m³
DNEL related information
Workers - Hazard via dermal route
Systemic effects
Long term exposure
- Hazard assessment conclusion:
- DNEL (Derived No Effect Level)
- Value:
- 0.45 mg/kg bw/day
- Most sensitive endpoint:
- repeated dose toxicity
- Route of original study:
- Oral
DNEL related information
- DNEL derivation method:
- ECHA REACH Guidance
- Overall assessment factor (AF):
- 100
- Dose descriptor starting point:
- NOAEL
- Value:
- 45 mg/kg bw/day
- Modified dose descriptor starting point:
- NOAEL
- Value:
- 45 mg/kg bw/day
- Explanation for the modification of the dose descriptor starting point:
The administration of 2-methylbut-3-yn-2-ol by gavage to male and female Wistar rats for 3 months caused signs of systemic toxicity manifested next to others on kidneys of male animals at dose levels beyond 45 mg/kg bw/d. Increased absolute and relativekidneyweights ofmaleswere regarded as treatment-related as there as both a macroscopic (enlarged, discoloration) and a histological correlate (increased eosinophilic droplets graded moderate to severe). Additionally, increased basophilic tubules and tubular casts were seen in these test groups. Findings in the kidney of male animals were assessed as treatment-related and adverse. Therefore, the starting point for DNEL derivation was set to 45 mg/kg bw/d.
- AF for dose response relationship:
- 1
- Justification:
- default value according to ECHA REACH Guidance: normal dose response relationship
- AF for differences in duration of exposure:
- 2
- Justification:
- default value according to ECHA REACH Guidance: extrapolation from subchronic to chronic exposure
- AF for interspecies differences (allometric scaling):
- 4
- Justification:
- default value according to ECHA REACH Guidance: allometric scaling from rat to human
- AF for other interspecies differences:
- 1
- Justification:
- default value according to ECHA REACH Guidance: no further interspecies differences expected
- AF for intraspecies differences:
- 5
- Justification:
- default value according to ECHA REACH Guidance
- AF for the quality of the whole database:
- 1
- Justification:
- default value according to ECHA REACH Guidance: modern guideline study
- AF for remaining uncertainties:
- 2.5
- Justification:
- default value according to ECHA REACH Guidance
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:
- medium hazard (no threshold derived)
Additional information - workers
General Population - Hazard via inhalation route
Systemic effects
Long term exposure
- Hazard assessment conclusion:
- hazard unknown but no further hazard information necessary as no exposure expected
Acute/short term exposure
- Hazard assessment conclusion:
- hazard unknown but no further hazard information necessary as no exposure expected
DNEL related information
Local effects
Long term exposure
- Hazard assessment conclusion:
- hazard unknown but no further hazard information necessary as no exposure expected
Acute/short term exposure
- Hazard assessment conclusion:
- hazard unknown but no further hazard information necessary as no exposure expected
DNEL related information
General Population - Hazard via dermal route
Systemic effects
Long term exposure
- Hazard assessment conclusion:
- hazard unknown but no further hazard information necessary as no exposure expected
Acute/short term exposure
- Hazard assessment conclusion:
- hazard unknown but no further hazard information necessary as no exposure expected
DNEL related information
Local effects
Long term exposure
- Hazard assessment conclusion:
- hazard unknown but no further hazard information necessary as no exposure expected
Acute/short term exposure
- Hazard assessment conclusion:
- hazard unknown but no further hazard information necessary as no exposure expected
General Population - Hazard via oral route
Systemic effects
Long term exposure
- Hazard assessment conclusion:
- hazard unknown but no further hazard information necessary as no exposure expected
Acute/short term exposure
- Hazard assessment conclusion:
- hazard unknown but no further hazard information necessary as no exposure expected
DNEL related information
General Population - Hazard for the eyes
Local effects
- Hazard assessment conclusion:
- hazard unknown but no further hazard information necessary as no exposure expected
Additional information - General Population
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.
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