Registration Dossier
Registration Dossier
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EC number: 231-555-9 | CAS number: 7632-00-0
Toxicological Summary
Administrative data
Workers - Hazard via inhalation route
Systemic effects
Long term exposure
- Hazard assessment conclusion:
- DNEL (Derived No Effect Level)
- Value:
- 2 mg/m³
- Most sensitive endpoint:
- repeated dose toxicity
DNEL related information
- Overall assessment factor (AF):
- 500
Acute/short term exposure
- Hazard assessment conclusion:
- DNEL (Derived No Effect Level)
- Value:
- 2 mg/m³
- Most sensitive endpoint:
- repeated dose toxicity
DNEL related information
- Overall assessment factor (AF):
- 500
Local effects
Acute/short term exposure
DNEL related information
Workers - Hazard via dermal route
Systemic effects
Acute/short term exposure
DNEL related information
Workers - Hazard for the eyes
Additional information - workers
No DNELs for systemic dermal exposure are needed since sodium nitrite does not pass the skin in significant amounts and needs no classification for dermal toxicity. Local dermal DNELs are not quantifiable due to a lack in data; however, the skin irritating property of the material is low. Oral toxicity is rather high in rats (LD50 values ca. 180 mg/kg) and the NOAEL in a 2 years drinking water study was 130 -150 mg/kg bw. The similarity of both values indicates a steep dose-effect relation and a low impact of exposure time. The toxicity in adult persons is considered to be about 10-fold higher than in the rat (assessment factors: 4 for for allometry and 2.5 for additional differences since rats show a much higher activity of the detoxificating enzyme MetHb reductase than man). An additional assessment factor of 5, however, is proposed from interindividual variations in sensitivity regarding possible variations in the detoxification enzyme MetHb reductase activity. Furthermore, due to the steep slope of the dose effect relation and the adversity of effects an additional assessment factor of 2 is considered. In humans, signs of toxicity have occationally been observed from doses of 5 mg/kg bw onwards. A virtual oral DNEL of 1.3 mg/kg bw (for the slow uptake via drinking water) would result from this deliberation (100 mg per person and day). WHO proposes an ADI-value of 0.2 mg/kg bw; this value takes into account the considerably higher sensitivity of infants and intrauterine life towards metHb forming agents. The inhalation exposure may be assessed in a similar manner as the (non-bolus) exposure via drinking water. Therefore, a DNEL for the workplace would, in theory, be roughly equivalent to an airborne concentration of 10 mg/m3 which, however, would be higher than general nuisance levels in many countries. Therefore, a DNEL of 2 mg/m3 is considered to be appropriate and to protect also from irritation.
General Population - Hazard via inhalation route
Systemic effects
Acute/short term exposure
DNEL related information
Local effects
Acute/short term exposure
DNEL related information
General Population - Hazard via dermal route
Systemic effects
Acute/short term exposure
DNEL related information
General Population - Hazard via oral route
Systemic effects
Acute/short term exposure
DNEL related information
General Population - Hazard for the eyes
Additional information - General Population
No DNELs are derived for the general population, nitrite levels in food and drinking water are regulated in most countries.
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