Registration Dossier
Registration Dossier
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EC number: 203-788-6 | CAS number: 110-65-6
Toxicological Summary
Administrative data
Workers - Hazard via inhalation route
Systemic effects
Long term exposure
- Hazard assessment conclusion:
- DNEL (Derived No Effect Level)
- Value:
- 1.25 mg/m³
- Most sensitive endpoint:
- repeated dose toxicity
- Route of original study:
- By inhalation
DNEL related information
- DNEL derivation method:
- ECHA REACH Guidance
- Overall assessment factor (AF):
- 20
- Dose descriptor starting point:
- NOAEC
- Value:
- 25 mg/m³
- AF for dose response relationship:
- 1
- Justification:
- NOAEC valued used as POD
- AF for differences in duration of exposure:
- 2
- Justification:
- substance specific duration adjustment: the degree of severity does not increase with longer duration of exposure based on the inhalation study (EU RAR), therefore AF of 2 is proposed instead of 6.
- AF for interspecies differences (allometric scaling):
- 1
- Justification:
- inhalatory route of exposure
- AF for other interspecies differences:
- 1
- Justification:
- metabolic rate scaling for nhalation exposure
- AF for intraspecies differences:
- 5
- Justification:
- worker population
- AF for the quality of the whole database:
- 1
- AF for remaining uncertainties:
- 2
- Justification:
- AF for breathing volumes
Acute/short term exposure
- Hazard assessment conclusion:
- DNEL (Derived No Effect Level)
- Value:
- 100 mg/m³
- Most sensitive endpoint:
- repeated dose toxicity
- Route of original study:
- By inhalation
DNEL related information
- DNEL derivation method:
- other: EU RAR
Local effects
Long term exposure
- Hazard assessment conclusion:
- DNEL (Derived No Effect Level)
- Value:
- 0.5 mg/m³
- Most sensitive endpoint:
- irritation (respiratory tract)
DNEL related information
- DNEL derivation method:
- other: OECL as recommended by SCOEL (2011)
- Dose descriptor:
- NOAEC
- Value:
- 0.5 mg/m³
Acute/short term exposure
- Hazard assessment conclusion:
- DNEL (Derived No Effect Level)
- Value:
- 1 mg/m³
- Most sensitive endpoint:
- irritation (respiratory tract)
DNEL related information
- DNEL derivation method:
- other: EU RAR
- Overall assessment factor (AF):
- 4
- Dose descriptor starting point:
- LOAEC
- Value:
- 5 mg/m³
- AF for remaining uncertainties:
- 4
- Justification:
- EU RAR approach:
LOAEC from subacute study was taken as POD. Therefore, the AF for duration was 2, only to adjust for 8-hour exposure. Additional uncertainty is covered by AF 2 - LOAEC/NAEC.
Workers - Hazard via dermal route
Systemic effects
Long term exposure
- Hazard assessment conclusion:
- DNEL (Derived No Effect Level)
- Value:
- 0.2 mg/kg bw/day
- Most sensitive endpoint:
- repeated dose toxicity
- Route of original study:
- By inhalation
DNEL related information
- DNEL derivation method:
- ECHA REACH Guidance
- Overall assessment factor (AF):
- 40
- Dose descriptor starting point:
- NOAEC
- Value:
- 25 mg/m³
- Modified dose descriptor starting point:
- NOAEL
- Value:
- 7.2 mg/kg bw/day
- Explanation for the modification of the dose descriptor starting point:
Experimental studies with repeated dose dermal exposure to butynediol are not available. Dermal risk assessment is based on subacute inhalation study.
100% absorption is assumed in both cases. Kinetics of absorption and bioavailability are more similar for inhalation and dermal routes, for the oral route (EU RAR).
The starting point is NOAEC of 25 mg/m3 which cooresponds to an intake of 7.2 mg/kg/day (respiratory rate of 0.8 L/min.kg for rat, 6 hours a day).
- AF for dose response relationship:
- 1
- Justification:
- NOAEC as POD
- AF for differences in duration of exposure:
- 2
- Justification:
- substance specific duration adjustment: the degree of severity does not increase with longer duration of exposure based on the inhalation study (EU RAR), therefore AF of 2 is proposed instead of 6.
- AF for interspecies differences (allometric scaling):
- 4
- Justification:
- human exposure route dermal, animal exposure route inhalatory (ECHA guidance)
- AF for other interspecies differences:
- 1
- Justification:
- covered by allometric scaling
- AF for intraspecies differences:
- 5
- Justification:
- worker population
- AF for the quality of the whole database:
- 1
- AF for remaining uncertainties:
- 1
Acute/short term exposure
- Hazard assessment conclusion:
- DNEL (Derived No Effect Level)
- Value:
- 6.6 mg/kg bw/day
- Most sensitive endpoint:
- acute toxicity
- Route of original study:
- Dermal
DNEL related information
- DNEL derivation method:
- ECHA REACH Guidance
- Overall assessment factor (AF):
- 100
- Dose descriptor starting point:
- other: LD50 dermal
- Value:
- 659 mg/kg bw/day
- AF for dose response relationship:
- 5
- Justification:
- lethal dose used as POD
- AF for interspecies differences (allometric scaling):
- 4
- Justification:
- human route of exposure dermal, animal route of exposure dermal (ECHA Guidance)
- AF for other interspecies differences:
- 1
- Justification:
- covered by allometric scaling
- AF for intraspecies differences:
- 5
- Justification:
- worker population
- AF for the quality of the whole database:
- 1
- AF for remaining uncertainties:
- 1
Local effects
Long term exposure
- Hazard assessment conclusion:
- high hazard (no threshold derived)
Acute/short term exposure
- Hazard assessment conclusion:
- high hazard (no threshold derived)
Workers - Hazard for the eyes
Local effects
- Hazard assessment conclusion:
- high 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
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