Registration Dossier
Registration Dossier
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EC number: 225-969-9 | CAS number: 5188-07-8
Toxicological Summary
Administrative data
Workers - Hazard via inhalation route
Systemic effects
Long term exposure
- Hazard assessment conclusion:
- DNEL (Derived No Effect Level)
- Value:
- 0.76 mg/m³
- Most sensitive endpoint:
- repeated dose toxicity
DNEL related information
- Overall assessment factor (AF):
- 25
- Modified dose descriptor starting point:
- NOAEC
Acute/short term exposure
- Hazard assessment conclusion:
- no data available: testing technically not feasible
DNEL related information
Local effects
Long term exposure
- Hazard assessment conclusion:
- no data available: testing technically not feasible
Acute/short term exposure
- Hazard assessment conclusion:
- no data available: testing technically not feasible
DNEL related information
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
DNEL related information
- Overall assessment factor (AF):
- 36
- Modified dose descriptor starting point:
- NOAEL
Acute/short term exposure
- Hazard assessment conclusion:
- no-threshold effect and/or no dose-response information available
DNEL related information
Local effects
Long term exposure
- Hazard assessment conclusion:
- no-threshold effect and/or no dose-response information available
Acute/short term exposure
- Hazard assessment conclusion:
- no-threshold effect and/or no dose-response information available
Workers - Hazard for the eyes
Additional information - workers
Long-term exposure - systemic effects
Dermal DNEL
DNEL derivation is based on a 8-week toxicity study by oral administration of sodium methylmercaptide to rats (Gaoua, 2005). The starting dose for DNEL calculation is a NOAEL of 15 mg/kg/day.
As default values, oral and dermal absorption were assumed to be 50 and 100%, respectively.
Application of assessment factors (ECETOC, TR no110, 2010) of:
- 4 for interspecies differences,
- 3 for intraspecies differences,
- 3 for exposure duration,
leads to a DNEL of 0.2 mg/kg bw/d for long-term dermal exposure - systemic effects.
Inhalation DNEL
Sodium methylmercaptide is used as a solution in water, therefore no inhalation DNEL will de derivated. However, due to potential release of methylmercaptan during use, the DNEL derivated for the registration dossier of methylmercaptan is reported.
DNEL derivation is based on a 13-week inhalation toxicity study of methylmercaptan to rats (Tansy et al., 1981).
The NOAEC for systemic toxicity was 17 ppm.Step 1) Relevant dose-descriptor
* NOAEC rat, 7 hours/day, 5 days/week = 17 ppm
Step 2) Modification of starting point:
* Correction of exposure duration in study (7 hrs/day, 5 days/week) to default worker exposure (8 hrs/day, 5 days/ week)
* Correction for activity driven differences of respiratory volumes in workers compared to workers in rest: 6.7 m3/10 m3
Step 3) Assessment factors
* Interspecies: 2.5
For inhalation studies only a factor 2.5 is used, and no correction is made for differences in body size, because extrapolation is based on toxicological equivalence of a concentration of a chemical in the air of experimental animals and humans; animal and humans breathe at a rate depending on their caloric requirements.
* Intraspecies : 5
* Exposure duration : 2
* Dose response: 1
* Quality of database: 1
DNEL Value based on NOAEC 13-w/rats :
17 x 7/8 x 5/7 x 6.7/10 x 1/(2.5 x 5 x 2 x 1 x 1) =0.39 ppm (0.76 mg/m3)
General Population - Hazard via inhalation route
Systemic effects
Long term exposure
- Hazard assessment conclusion:
- exposure based waiving
Acute/short term exposure
- Hazard assessment conclusion:
- exposure based waiving
DNEL related information
Local effects
Long term exposure
- Hazard assessment conclusion:
- exposure based waiving
Acute/short term exposure
- Hazard assessment conclusion:
- exposure based waiving
DNEL related information
General Population - Hazard via dermal route
Systemic effects
Long term exposure
- Hazard assessment conclusion:
- exposure based waiving
Acute/short term exposure
- Hazard assessment conclusion:
- exposure based waiving
DNEL related information
Local effects
Long term exposure
- Hazard assessment conclusion:
- exposure based waiving
Acute/short term exposure
- Hazard assessment conclusion:
- exposure based waiving
General Population - Hazard via oral route
Systemic effects
Long term exposure
- Hazard assessment conclusion:
- exposure based waiving
Acute/short term exposure
- Hazard assessment conclusion:
- exposure based waiving
DNEL related information
General Population - Hazard for the eyes
Additional information - General Population
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