Registration Dossier
Registration Dossier
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EC number: 603-923-2 | CAS number: 135590-91-9
Toxicological Summary
Administrative data
Workers - Hazard via inhalation route
Systemic effects
Long term exposure
- Hazard assessment conclusion:
- DNEL (Derived No Effect Level)
- Value:
- 7 mg/m³
- Most sensitive endpoint:
- repeated dose toxicity
DNEL related information
- Overall assessment factor (AF):
- 12.5
- Dose descriptor starting point:
- NOAEL
- Value:
- 50 mg/kg bw/day
- Modified dose descriptor starting point:
- NOAEC
- Value:
- 88.2 mg/m³
- Explanation for the modification of the dose descriptor starting point:
The conversion of an oral NOAEL into an inhalatory NOAEC is calculated according to ECHA guidance document "Guidance on information requirements and chemical safety assessment. Chapter R.8: Characterisation of dose [concentration]-response for human health", May 2008. In the ECHA Guidance a factor of 2 is suggested for the extrapolation from oral to inhalation absorption. On the contrary, the Technical guidance document on risk assessment in support of Commission directive 93/67/EEC, 2003 appendix IV A and B gives a number of physico-chemical properties that normally determine oral, inhalation and dermal absorption. These parameters include molecular weight, log Kow, pKa values and for inhalation also particle size distribution, vapour pressure etc. Molecules with a molecular weight < 500 and a log KOW between 0 and 4 can be assumed to be well absorbed equivalently by the oral and inhalation route. Oral absorption may be reduced for acids and bases depending on their pKa value and their possibility of absorption in the GI tract. More lipophilic substances may be better absorbed in the GI tract due to the solubilisation with bile acids and thus oral absorption may be higher than inhalation absorption. The consideration of physico-chemical parameters should be performed before using default assumptions. Unless valid data suggest that inhalation leads to higher absorption than oral ingestion, equal absorption will be assumed when extrapolating from oral to inhalation route.
Acute/short term exposure
- Hazard assessment conclusion:
- no hazard identified
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:
- 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:
- 6 mg/kg bw/day
- Most sensitive endpoint:
- repeated dose toxicity
DNEL related information
- Overall assessment factor (AF):
- 50
- Dose descriptor starting point:
- NOAEL
- Value:
- 300 mg/kg bw/day
- Explanation for the modification of the dose descriptor starting point:
For a 6-hour exposure period, which is considered to be most relevant with a view on the worker exposure under the conditions of practical use, the dermal penetration rate of Mefenpyr-diethyl is estimated to be 1.3% for the undiluted product and 19.2% for the aqueous dilution (Maas, J. et al., 1994). Assuming a dermal absorption of 19.2% as a very conservative approach and applying this value to the most relevant chronic oral NOAEL of 50 mg/kg bw/d, the calculated chronic dermal NOAEL would be 260 mg/kg bw/d. Hence, no additional assessment factor for exposure duration has to be applied.
Acute/short term exposure
- Hazard assessment conclusion:
- no hazard identified
DNEL related information
- Dose descriptor starting point:
- NOAEL
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
General Population - Hazard via inhalation route
Systemic effects
Long term exposure
- Hazard assessment conclusion:
- DNEL (Derived No Effect Level)
- Value:
- 1.7 mg/m³
- Most sensitive endpoint:
- repeated dose toxicity
DNEL related information
- Overall assessment factor (AF):
- 25
- Dose descriptor starting point:
- NOAEL
- Value:
- 50 mg/kg bw/day
- Modified dose descriptor starting point:
- NOAEC
- Value:
- 43.5 mg/m³
- Explanation for the modification of the dose descriptor starting point:
The conversion of an oral NOAEL into an inhalatory NOAEC is calculated according to ECHA guidance document "Guidance on information requirements and chemical safety assessment. Chapter R.8: Characterisation of dose [concentration]-response for human health", May 2008. In the ECHA Guidance a factor of 2 is suggested for the extrapolation from oral to inhalation absorption. On the contrary, the Technical guidance document on risk assessment in support of Commission directive 93/67/EEC, 2003 appendix IV A and B gives a number of physico-chemical properties that normally determine oral, inhalation and dermal absorption. These parameters include molecular weight, log Kow, pKa values and for inhalation also particle size distribution, vapour pressure etc. Molecules with a molecular weight < 500 and a log KOW between 0 and 4 can be assumed to be well absorbed equivalently by the oral and inhalation route. Oral absorption may be reduced for acids and bases depending on their pKa value and their possibility of absorption in the GI tract. More lipophilic substances may be better absorbed in the GI tract due to the solubilisation with bile acids and thus oral absorption may be higher than inhalation absorption. The consideration of physico-chemical parameters should be performed before using default assumptions. Unless valid data suggest that inhalation leads to higher absorption than oral ingestion, equal absorption will be assumed when extrapolating from oral to inhalation route.
Acute/short term exposure
- Hazard assessment conclusion:
- no hazard identified
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:
- 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:
- 3 mg/kg bw/day
- Most sensitive endpoint:
- repeated dose toxicity
DNEL related information
- Overall assessment factor (AF):
- 100
- Dose descriptor starting point:
- NOAEL
- Value:
- 300 mg/kg bw/day
- Explanation for the modification of the dose descriptor starting point:
For a 6-hour exposure period, which is considered to be most relevant with a view on the worker exposure under the conditions of practical use, the dermal penetration rate of Mefenpyr-diethyl is estimated to be 1.3% for the undiluted product and 19.2% for the aqueous dilution (Maas, J. et al., 1994). Assuming a dermal absorption of 19.2% as a very conservative approach and applying this value to the most relevant chronic oral NOAEL of 50 mg/kg bw/d, the calculated chronic dermal NOAEL would be 260 mg/kg bw/d. Hence, no additional assessment factor for exposure duration has to be applied.
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:
- 0.5 mg/kg bw/day
- Most sensitive endpoint:
- repeated dose toxicity
- Route of original study:
- Oral
DNEL related information
- Overall assessment factor (AF):
- 100
- Dose descriptor starting point:
- NOAEL
- Value:
- 50 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
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