Ammonium nitrate

Endpoint summary

Description of key information

The acute oral and dermal toxicity (LD50) is >2000 and >5000 mg/kg bw, respectively for ammonium nitrate. The acute inhalation toxicity is not tested, the vapour pressure is negligilbe and the particle size of ammonium nitrate shows no inhalable fraction.

Key value for chemical safety assessment

Acute toxicity: via oral route

Link to relevant study records

Reference

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Sept-Oct. 1981

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Remarks:

Study performed before GLP was in place and comparable to guidelines.

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 401 (Acute Oral Toxicity)

GLP compliance:

no

Test type:

other: acute oral median lethal dose

Species:

rat

Strain:

Wistar

Sex:

male/female

Route of administration:

oral: gavage

Vehicle:

other: methylcellulose and Tween 80

Doses:

Range finder: 50, 250, 1250, 5000 mg/kg
Definitive: 2000, 2380, 2830, 3360 mg/kg

No. of animals per sex per dose:

Range finder: 2
Definitive: 5

Control animals:

not specified

Preliminary study:

The mortalities indicated an LD50 in the range 1250-5000 mg/kg.

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

2 950 mg/kg bw

Mortality:

Mortality occurred at 3360 (7/10), 2830 (3/10), 2380 (4/10) mg/kg and also 1 animal in 2000 mg/kg.

Clinical signs:

other: Prostration, lethargy and deep rapid breathing were the main clinical signs. All surviving animals appeared normal at day 1, except at the highest dose tested animals appeared normal at day 2.

Gross pathology:

For animals that died, congested lungs was the major pathological finding.

Interpretation of results:

Category 5 based on GHS criteria

Remarks:

Not classified according to Regulation (EC) No 1272/2008

Conclusions:

LD50 = 2950 mg/kg bw

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

2 000 mg/kg bw

Quality of whole database:

The study has klimisch code 2.

Acute toxicity: via inhalation route

Endpoint conclusion

Endpoint conclusion:

no study available

Value:

mg/m³ air

Acute toxicity: via dermal route

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

5 000 mg/kg bw

Quality of whole database:

The study has klimisch code 1.

Additional information

Acute oral toxicity:

Based on a reliable prior to GLP performed acute oral study in rats with ammonium nitrate the LD50 is considered to be 2950 mg/kg bw. Mortality occurred at 3360 (7/10), 2830 (3/10), 2380 (4/10) mg/kg and also 1 animal in 2000 mg/kg. Prostration, lethargy and deep rapid breathing were the main clinical signs. All surviving animals appeared normal at day 1, except at the highest dose tested animals appeared normal at day 2. All surviving animals showed body weight gains. For animals that died, congested lungs was the major pathological finding.

All oral acute studies with reliability 4 reported LD50 values above 2000 mg/kg bw. Therefore the oral LD50 for ammonium nitrate is considered to be >2000 mg/kg bw.

Acute dermal toxicity:

Based on a reliable, OECD 402 acute dermal toxicity study in rats with ammonium nitrate itself, the LD50 is shown to be >5000 mg/kg bw. No effects on bodyweight, clinical signs, gross pathology and mortality have been observed.

Acute inhalation toxicity:

No reliable acute inhalation study is available for ammonium nitrate, but as the vapour pressure is considered negligible and the particle size of ammonim nitrate shows no inhalable fraction (0% < 100 µm) it is clear that no study is required according to REACH Annex VIII.

Justification for selection of acute toxicity – oral endpoint

One acute oral key study is available.

Justification for selection of acute toxicity – dermal endpoint

One acute dermal study is available.

Justification for classification or non-classification

Based on the data available, ammonium nitrate does not have to classified for acute toxicity, according to Regulation (EC) No 1272/2008. According to GHS the substance is classified as Category 5 for oral toxicity, however this is not implemented in the EU and therefore not applicable.