Registration Dossier

Administrative data

Endpoint:
acute toxicity: inhalation
Type of information:
experimental study
Adequacy of study:
key study
Study period:
1967-03-22 to 1967-04-05
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Study predating guidelines and GLP, but performed close to OECD TG 403.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1967
Report Date:
1967

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 403 (Acute Inhalation Toxicity)
Deviations:
not applicable
Principles of method if other than guideline:
Based on H.F. Smyth et al.: Am. Ind. Hyg. Ass. J. 23, 95-107 (1962)
GLP compliance:
no
Test type:
standard acute method
Limit test:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material: N-Acetylmorpholin

Test animals

Species:
rat
Strain:
not specified
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Two group weights at study initiation: 1280 g (28.03., 3 males / 3 females); 1325 g (29.03., 3 males / 3 females)

ENVIRONMENTAL CONDITIONS
- no data

IN-LIFE DATES: From: 1967-03-29 To: 1967-04-05

Administration / exposure

Route of administration:
inhalation: vapour
Type of inhalation exposure:
whole body
Vehicle:
air
Details on inhalation exposure:
GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: not specified
- Exposure chamber volume: not specified
- Method of holding animals in test chamber: not specified
- Source and rate of air: not specified
- System of generating vapour: bubbling 200 L/h air through a substance column of about 5 cm above a fritted glass disc in a glass cylinder for 8 hours
- Temperature, humidity, pressure in air chamber: at 20°C, nothing else specified

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

TEST ATMOSPHERE
- Particle size distribution: not applicable (vapour)
Analytical verification of test atmosphere concentrations:
no
Duration of exposure:
8 h
Concentrations:
Calculation from vapour pressure of test item:

Concentration = VP / TP * 1000000 * MW / MVo
= 0.022 / 1013 * 1000000 * 129.16 /22.414 = 125 mg/m³ or 0.125 mg/L air
Where:
- Vapour pressure (VP): 0.022 hPa
- Total pressure (TP): 1013 mm Hg
- Molecular weight (MW): 129.16
- MolVolume (MVo): 22.414


Nominal concentrations from raw data:
Group 1a.: 0.1685 g/L (269.54 g test item / 1600 L air)
Group 1b.: 0.1700 g/L (271.93 g test item / 1600 L air)
Group 2a.: 0.1374 g/L (219.87 g test item / 1600 L air)
Group 2b.: 0.1388 g/L (222.06 g test item / 1600 L air)

No. of animals per sex per dose:
12 males, 12 females
Control animals:
no
Details on study design:
two groups (6 males, 6 females each) exposed for 8h each
Group 1: 28. 3.1967
Group 2: 29. 3.1967
- Duration of observation period following administration: 7 days
- Frequency of observations and weighing: body weight taken at study start and end
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs (groupwise)
Statistics:
not performed

Results and discussion

Preliminary study:
Considering the relatively low vapour pressure of 0.022 mg Hg at 20°C, the calculated test item concentration of 170 mg/L air was implausibly high. The saturated atmospere calculated from the vapour pressure is 1.7 mg/L.
Effect levels
Sex:
male/female
Dose descriptor:
LC0
Effect level:
> 0.125 mg/L air (nominal)
Based on:
test mat.
Exp. duration:
8 h
Remarks on result:
other: Calculated from vapour pressure (0.027 hPa at 20°C)
Mortality:
No mortality occurred
Clinical signs:
other: None
Body weight:
Both groups gained body weight between day 1 and day 7:
Total group 1, day 1: 1280 g; day 7: 1415 g
Total group 2, day 1: 1325 g; day 7: 1433 g
Gross pathology:
chronic bronchitis (1x)
Other findings:
None

Any other information on results incl. tables

No mortalities after 8-hour exposure to an atmosphere enriched with the substance at 20°C.

Applicant's summary and conclusion