N,N-dimethylbutylamine

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

1975

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

other: Screening level information. Information insufficient.

Data source

Reference

Reference 1

Reference Type:

other: interoffice memo

Title:

Unnamed

Year:

2002

Report date:

2002

Reference 2

Reference Type:

other: TSCA 8e submission

Title:

Unnamed

Year:

1975

Report date:

1975

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

Deviations:

yes

Remarks:

; pre-guideline study. Only 2 dose levels were tested with an inappropriate spacing factor (100). No analytical dose monitoring. Test atmosphere generationis not clearly described.

Principles of method if other than guideline:

Method: other: no data

GLP compliance:

no

Remarks:

pre-GLP study

Test type:

fixed concentration procedure

Limit test:

no

Test material

Test material information

Constituent 1

Test material form:

aerosol dispenser: not specified

Remarks:

migrated information: aerosol

Details on test material:

- Physical state: clear liquid

Test animals

Species:

rat

Strain:

other: Charles River CD-1

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River
- Weight at study initiation: 205-230 g
- Housing: groups of 5 by sex in metal cages
- Diet: ad libitum
- Water: ad libitum

ENVIRONMENTAL CONDITIONS
- Temperature (°C): not reported but controlled
- Humidity (%): not reported but controlled

Administration / exposure

Route of administration:

inhalation: mist

Type of inhalation exposure:

whole body

Vehicle:

air

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: glass chamber
- Exposure chamber volume: 59.1 L
- Method of holding animals in test chamber: rats were placed into subunits of 2 or 3 rats each
- System of generating aerosols: no details reported. Concentration was controlled by the air volume and the test substance flow (2.0 mg/L level: Havard Infusion Pump; 200 mg/L: Dow Dual Syringe Feeder)


TEST ATMOSPHERE
- Brief description of analytical method used: no measurements performed
- Samples taken from breathing zone: yes/no

Analytical verification of test atmosphere concentrations:

no

Duration of exposure:

4 h

Concentrations:

approx. 2 mg/L and 200 mg/L

No. of animals per sex per dose:

5

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: no details reported
- Necropsy of survivors performed: no
- Other examinations performed: clinical signs, body weight

Results and discussion

Effect levels

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 2 - < 200 mg/L air

Based on:

test mat.

Exp. duration:

4 h

Remarks on result:

other: concentrations calculated

Mortality:

no mortality at 2 mg/L (0/10)
all rats died at 200 mg/L within 11 minutes following initiation of the exposure

Clinical signs:

other: Groups at 2 mg/L: during exposure: decreased motor activity, erythema, salivation, lacrimation, clear nasal discharge, both ocular and nasal porphyrin discharge, tachypnea, dyspnea, gasping, soft stool, intermittent tonic convulsions, prostration. During

Body weight:

Groups at 2 mg/L: all rats gained body weight during the 14-day observation period

Gross pathology:

Groups at 200 mg/L: lungs were affected, see table below

Any other information on results incl. tables

Necropy findings in rats of groups at 200 mg/L: lungs were affected, see table below

 

Finding			Incidence males	Incidence females
lungs	congestion	slight	1/5	2/5
		Moderate	4/5	2/5
		marked		1/5
lungs	oedematous		5/5	5/5
Lungs, right cardia lobe consolidated			1/5

 

Applicant's summary and conclusion

Conclusions:

Dimethylbutylamine is a strong respiratory irritant.

Executive summary:

The acute inhalation toxicity was determined in CD-1 rats (5 per sex and dose) in a pre-guideline study without monitoring of the test substance concentration. All rats exposed at 2 mg/L survived until the end of the observation period while all rats exposed to nominal 200 mg/L died within 10 minutes after exposure initiation. Clinical signs indicated irritating effects both in the low dose and the high dose group (ocular and nasal discharge, corneal opacity in surviving animals; lung congestion and lung edema in victims). Thus the (LC50_{(4 hrs)} was between 2 mg/L and 200 mg/l in this study (Wazeter and Goldenthal, 1975).

The study does not allow estimating the LC₅₀-value. However, the described signs of toxicity clearly indicate that the primary mode of action is the irritating and corrosive effect of Dimethylbutylamine. The study is therefore considered to be supportive for assessment.