m-phenylenediamine

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1982

Report date:

1982

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

Deviations:

yes

Remarks:

partical size distribution not monitored; temperature, humidity, and pressure in chambers not reported

GLP compliance:

not specified

Test type:

standard acute method

Test material

Test material information

Constituent 1

Reference substance name:

m-phenylenediamine

EC Number:

203-584-7

EC Name:

m-phenylenediamine

Cas Number:

108-45-2

Molecular formula:

C6H8N2

IUPAC Name:

m-phenylenediamine

Details on test material:

- Purity: 99.5%

Test animals

Species:

rat

Strain:

other: Crl:CD

Sex:

male

Details on test animals or test system and environmental conditions:

TEST ANIMALS
-Age at study initiation: 7-8 weeks
- Weight at study initiation: 236 - 278 grams
- Fasting period before study: not reported
- Housing: in pairs in 8"x8"x14" stainless steel cages
- Diet (e.g., ad libitum): ad libitum
- Water (e.g., ad libitum): ad libitum
- Acclimation period: 1 week

ENVIRONMENTAL CONDITIONS
-Temperature (ºC): not reported
- Humidity (%): not reported
- Air changes (per hr): not reported
- Photoperiod (hrs dark / hrs light): not reported

Administration / exposure

Route of administration:

inhalation: aerosol

Type of inhalation exposure:

nose only

Vehicle:

other: Nitrogen

Details on inhalation exposure:

Animals were exposed nose-only for single 4-hour periods to atmospheres containing MPD.
Generation: The test material was heated (146-188 ºC) in a round bottom flask. Heated nitrogen (52-75 ºC) was blown through the flask, sweeping MPD vapors into a dilution air stream. Prior to chamber entry, oxygen was added to this mixture to assure a final chamber O2 concentration >20%.

Analytical verification of test atmosphere concentrations:

yes

Remarks:

Test atmospheres were sampled by drawing chamber atmosphere through a fritted glass impinger containing methanol as the trapping solvent. Samples were analyzed on a Hewlett-Packard 5700A Gas Chromotograph equipped with a flame ionization detector.

Duration of exposure:

4 h

Concentrations:

Mean: 0.72, 2.0, 3.2, 3.9 mg/L

No. of animals per sex per dose:

10

Control animals:

not specified

Details on study design:

During exposure all rats were observed, clinical signs noted, and chamber oxygen content and temperature monitored. Following exposure, all surviving rats were weighed and observed for 14 days.

Results and discussion

Effect levels

Effect levels 1

Sex:

male

Dose descriptor:

LC50

Effect level:

3.2 mg/L air (analytical)

95% CL:

> 2.6 - < 4.1

Exp. duration:

4 h

Effect levels 2

Sex:

male

Dose descriptor:

other: LOAEL

Effect level:

0.72 mg/L air

Exp. duration:

4 h

Remarks on result:

other: At all concentrations, rats exhibited red ocular and nasal discharge.

Mortality:

Deaths occurred 1-7 days post exposure.

Clinical signs:

other: At all concentrations, rats exhibited red ocular and nasal discharge. Rats at all concentrations showed hair loss and wet perineum. Lung noise, brown stained fur, pallor, and tremors were observed at concentrations ≥ 2.0 mg/L. Labored breathing, dry re

Body weight:

At all concentrations, rats exhibited moderate to severe weight loss for 1-3 days followed by weight gain.

Other findings:

Upon contact with the cool dilution air, the test substance's vapors condensed into an aerosol. The resulting atmosphere was visible to the unaided eye. Chamber temperature was ≤ 31 ºC and oxygen content was ≥ 20% for all exposures.

Applicant's summary and conclusion

Interpretation of results:

Category 4 based on GHS criteria

Conclusions:

4-hour LC50 = 3.2 mg/L

Executive summary:

An inhalation Median Lethal Concentration for the test substance was determined in male Crl:CD^®rats given single 4 -hour exposures. The calculated LC50 is 3.2 mg/L with 95% confidence limits of 2.6 and 4.1 mg/L.