N-methylisopropylamine

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline study conducted according to GLP.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2008

Report date:

2008

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

Version / remarks:

(1981)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.2 (Acute Toxicity (Inhalation))

Version / remarks:

(1992)

Deviations:

no

Test guideline 3

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.1300 (Acute inhalation toxicity)

Version / remarks:

(1998)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test type:

standard acute method

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

N-methylisopropylamine

EC Number:

225-266-7

EC Name:

N-methylisopropylamine

Cas Number:

4747-21-1

Molecular formula:

C4H11N

IUPAC Name:

methyl(propan-2-yl)amine

Details on test material:

- Name of test material (as cited in study report): N-Methylisopropylamine
- Physical state: liquid, yellowish
- Analytical purity: > 99.9 area% (analytical report 07L00393)
- Lot/batch No.: 8078/06/056
- Stability under test conditions: the stability under storage conditions over the study period was guaranteed by the manufacturer, and the manufacturer holds this responsibility.
- Storage condition of test material: room temperature, in the dark

Test animals

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: RCC Ltd Laboratory Animal Services, CH-4414 Füllinsdorf, Switzerland
- Age at study initiation: males approx. 7 - 8 weeks, females approx. 10 – 11 weeks
- Weight at study initiation: males, approx. 224 - 245 g, females approx. 194 - 207 g
- Housing: single housing in H-Temp (PSU) cages with a floor area of about 800 cm2 (TECNIPLAST, Germany)
- Diet (e.g. ad libitum): Kliba-Labordiaet (Maus/Ratte Haltung “GLP”), Provimi Kliba SA, Kaiseraugst, Basel, Switzerland; ad libitum
- Water (e.g. ad libitum): tap water, ad libitum
- Acclimation period: at least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 – 24
- Humidity (%): 30 - 70
- Air changes (per hr): not specified
- Photoperiod (hrs dark / hrs light): 12 / 12

Administration / exposure

Route of administration:

inhalation: vapour

Type of inhalation exposure:

whole body

Vehicle:

air

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE
The vapors were generated by supplying amounts of the test substance to a heated vaporizer (glasses with thermostat) by means
of the pump (continuous infusion pump perfusor); the generator temperature was set at 40 °C. The vapors that developed were taken up by the supply air and passed into the exposure system.

TEST ATMOSPHERE
The homogenous distribution of test substance atmosphere in the inhalation system had been verified with model vapors.
During each exposure, the following parameters were recorded four times at about 1-hour intervals:
- The temperature in the inhalation system were measured continuously with a digital thermometer.
- The humidity in the inhalation system were measured with a dielectric probe.
- The supplied air flow (compressed air) was adjusted at 3.0 m³/h and was continously measured with a flowmeter.
- The exhaust air flow was adjusted at 3.2 m³/h by a separate exhaust air system and continuously measured with a flowmeter.
The higher amounts of exhaust air, which were adjusted by means of a separate exhaust air system, achieved negative pressures inside the exposure system to ensure that no contamination of the laboratory occurred as result of possible leakage from the inhalation chambers.
The air changes were about 15 times per hour. Since air change was judged to be sufficient to prevent oxygen depletion by the breathing of the animals, and since the test item concentration was not considered to substantially influence oxygen partial pressure, no O2 measurement in the inhalation system was performed.

CHAMBER DESCRIPTION
Whole inhalation exposure chamber (IKA 02 glass-steel construction, BASF SE) with a volume of approx. 200 L; the animals were kept singly in compartmentalized wire cages, and were exposed inside the chamber. The exposure system was located inside an exhaust cabin in an air-conditioned laboratory.

Analytical verification of test atmosphere concentrations:

yes

Remarks:

(gas chromatographic method; Laboratory of Analytical Chemistry of the Experimental Toxicology and Ecology, BASF SE)

Duration of exposure:

4 h

Concentrations:

Nominal concentrations: 5.87 and 11.73 mg/L
Analytical concentrations: 4.99 and 10.12 mg/L

For each sample the concentration was calculated in mg/L from the analytically determined mass values of the test substance in the samples and the respective volume sampled from the inhalation atmosphere. Mean and standard deviation were calculated for the concentration from the results of the individual measurements

No. of animals per sex per dose:

Five

Control animals:

no

Details on study design:

DURATION OF THE OBSERVATIOn PERIOD
14 days
MORTALITY AND CLINICAL SYMPTOMS
A check for any dead or moribund animal was made twice each workday and once on Saturdays, Sundays and on public holidays. Detailed clinical observations were recorded for each animal separately several times during exposure and at least once on each workday of the observation period. No clinical examination was performed on public holidays or weekends.
BODY WEIGHT
Individual body weights were recorded shortly before exposure (day 0), weekly thereafter and at the end of the study. Additionally, body weight was measured in animals that died from study day 1 onward.
NECROPSY
At the end of the observation period the surviving animals were sacrificed by CO2-inhalation and were subjected to gross-pathological examination as were the animal which had died before. To clarify the gross-pathological findings, selected organs of individual animals were examined
histopathologically.

Statistics:

The LC50 was calculated by Probit analysis (Finney DJ, "Probit Analysis" Cambridge University Press, 1971) by means of a computer program. For results of the type ”LC50 greater than”, ”LC50 approx.”, or ”LC50 smaller than”, the binomial test was used for statistical evaluation (Steel RGD and Torrie JH, Principles and procedures of statistics a biometrical approach. McGraw - Hill, 1984).

Results and discussion

Effect levels

Effect levels 1

Sex:

male

Dose descriptor:

LC50

Effect level:

7.11 mg/L air (analytical)

Based on:

test mat.

Exp. duration:

4 h

Remarks on result:

other: 0% mortality at 4.99 mg/L and 100% mortality at 10.12 mg/L

Effect levels 2

Sex:

female

Dose descriptor:

LC50

Effect level:

9.39 mg/L air (analytical)

Based on:

test mat.

Exp. duration:

4 h

Remarks on result:

other: 0% mortality at 4.99 mg/L and 80% mortality at 10.12 mg/L

Effect levels 3

Sex:

male/female

Dose descriptor:

LC50

Effect level:

9.09 mg/L air (analytical)

Based on:

test mat.

Exp. duration:

4 h

Remarks on result:

other: 0% mortality at 4.99 mg/L and 90% mortality at 10.12 mg/L

Mortality:

In the test group treated with 4.99 mg/L test item, no mortality was observed in male and female animals.
In the test group treated with 10.12 mg/L test item, 4/5 females and 5/5 males died either during exposure or within study day 2 after the exposure.

Clinical signs:

other: Clinical signs of toxicity in animals exposed to 4.99 and 10.12 mg/L comprised visually increased respiration, abdominal respiration, gasping, respiration sounds, eyelid closure, red crusts formation of the eyes, salivation, colorless discharge and red cr

Body weight:

In the group exposed to 4.99 mg/L the mean body weights of the male animals increased throughout the study period. The mean body weights of the female animals decreased during the first post exposure observation week but increased during the second week.
In the group exposed to 10.12 mg/L the mean body weight of the surviving female animal decreased during the first post exposure observation
week but increased during the second week. However the body weight of the surviving female animal did not reach the initial level.

Gross pathology:

In the group exposed to 4.99 mg/L, gross pathological examination at necropsy revealed focal red discoloration of all lung lobes with partly sunken surface in all male animals and in one female animal at termination of the study. No gross pathological abnormalities were observed in the other four female animals.
In the group exposed to 10.12 mg/L, gross pathological examinationof the male and female animals died either during exposure or within study day 2 after the exposure, revealed focal red or dark red discoloration of the lung. In a few animals partly sunken surface of the lung was noted. In one male animal moderate dilation of the stomach with gaseous content was noted. At termination of the study, no gross pathological abnormality was noted in the one surviving female animal.

Other findings:

Histopathology of the lung of one representative male animal revealed slight acute diffuse congestion, slight acute diffuse alveolar edema and alveolar emphysema as well as severe to massive acute multifocal to coalescing necrosis of the bronchiolar epithelium.

Any other information on results incl. tables

Acute inhalation toxicity test with MIPA: details on clinical symptoms

Test Conc.(mg/L)	Findings	Animals (initially 5/sex)
		Males	Females
4.99	Mortality	0/5	0/5
	Abdominal respiration	+ (day 0 to 10)	+ (day 0 to 10)
	Anogenital region smeared with urine	+ (hour 1 to 24 of day 0)	+ (hour 1 to 24 of day 0)
	Attempts to escape	+ (during hour 1)	+ (during hour 1)
	Eyelid closure, both eyes	+ (hour 1 to 4 of day 0)	+ (hour 1 to 4 of day 0)
	Eyelid, crusts, red, left	-	+ (day 1)
	Gasping	+ (hour 1 to day 1)	+ (hour 1 to day 1)
	Nose, discharge, colorless	+ (hour 1 to 4 of day 0)	+ (hour 1 to 4 of day 0)
	Nose, margin, crust formation, red	+ (day 1 to 3)	+ (day 0 to 3)
	Piloerection	+ (hour 2 to day 1)	+ (hour 2 to day 1)
	Respiration sounds	+ (day 0 to 6)	+ (day 0 to 14
	Respiration, visually increased	+ (day 13 to 14)	+ (day 13 to 14)
	Salivation	+ (hour 1 to 24 of day 0)	+ (hour 1 to 24 of day 0)
	Squatting posture	+ (hour 4 to 24 of day 0)	+ (hour 4 to day 1)
	Wiping of snouts	+ (during hour 1)	+ (during hour 1)
10.12	Mortality	5/5	4/5
	Abdominal region smeared with urine	+ (hour 1 to 4 of day 0)	+ (hour 1 to 2 of day 0)
	Abdominal respiration	-	+ (day 5to 14)
	Attempts to escape	+ (during hour 1)	+ (during hour 1)
	Eye, discharge, colorless, both eyes	-	+ (day 0)
	Eyelid closure, both eyes	+ (hour 1 to 4 of day 0)	+ (hour 1 to 4 of day 0)
	Eyelid, crusts, red, both eyes	-	+ (day 1)
	Eyelid, swollen, both eyes	-	+ (day 0)
	Gasping	+ (hour 1 to 4 of day 0)	+ (hour 1 to day 2)
	Nose, crust formation, red	-	+ (hour 1 to day 6)
	Nose, discharge, colorless	+ (hour 1 to 4 of day 0)	+ (hour 1 to 24 of day 0)
	Nose, discharge, red	-	+ (day 1)
	Piloerection	+ (hour 2 to 4 of day 0)	+ (hour 2 to day 9)
	Reduced general state	-	+ (day 1 to day 5)
	Respiration sounds	-	+ (day 0 to day 14)
	Salivation	+ (hour 1 to 4 of day 0)	+ (hour 1 to 24 of day 0)
	Squatting posture	-	+ (day 0)
	Wiping of snouts	+ (hour 1 to 3 of day 0)	+ (hour 1 to 3 of day 0)

Acute inhalation toxicity test with MIPA: details on body weight changes

Test Conc.	4.99 mg/mL
	Males (5/group)						Females (5/group)
Day	Individual weights (g)					Mean weight (g)	Individual weights (g)					Mean weight (g)
	1	2	3	4	5		1	2	3	4	5
0	224.5	224.8	224.9	234.6	236.8	229.1	200.6	194.4	194.1	199.3	200.5	197.8
7	234.7	234.4	224.9	239.7	237.0	234.1	180.1	166.1	173.2	185.9	183.0	177.7
14	283.5	285.4	279.5	294.7	299.3	288.5	208.1	192.2	197.9	197.4	208	200.7
Test Conc.	10.12 mg/mL
	Males (5/group)						Females (5/group)
Day	Individual weights (g)					Mean weight (g)	Individual weights (g)					Mean weight (g)
	1	2	3	4	5		1	2	3	4	5
0	240.5	244.6	235.6	244.5	239.7	241.0	196.0	206.8	204.3	202.2	202.7	202.4
1	n.a.	n.a.	n.a.	n.a.	n.a.	n.a.	n.a.	183.6	176.1	n.r.	n.r.	179.9
2	n.a.	n.a.	n.a.	n.a.	n.a.	n.a.	n.a.	n.a.	n.a.	n.r.	171.6	171.6
7	n.a.	n.a.	n.a.	n.a.	n.a.	n.a.	n.a.	n.a.	n.a.	168.7	n.a.	168.7
14	n.a.	n.a.	n.a.	n.a.	n.a.	n.a.	n.a.	n.a.	n.a.	195.3	n.a.	195.3
n.a., not applicable since animal died, n.r., not recorded

Applicant's summary and conclusion

Interpretation of results:

Category 3 based on GHS criteria