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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Administrative data

Endpoint:
acute toxicity: inhalation
Type of information:
experimental study
Adequacy of study:
other information
Reliability:
3 (not reliable)
Rationale for reliability incl. deficiencies:
other: Pre-guideline study with significant methodolgical deficiencies. Concentration close to saturation but not measured.

Data source

Reference
Reference Type:
publication
Title:
Unnamed
Year:
1954
Report date:
1954

Materials and methods

Test guideline
Qualifier:
equivalent or similar to guideline
Guideline:
OECD Guideline 403 (Acute Inhalation Toxicity)
Deviations:
yes
Remarks:
concentration not measured
Principles of method if other than guideline:
Inhalation risk test. Exposure for 8 hours to a concentration approaching saturation.
GLP compliance:
no
Limit test:
no

Test material

Constituent 1
Chemical structure
Reference substance name:
2-methylvaleric acid
EC Number:
202-594-9
EC Name:
2-methylvaleric acid
Cas Number:
97-61-0
Molecular formula:
C6H12O2
IUPAC Name:
2-methylpentanoic acid

Test animals

Species:
rat
Strain:
not specified
Sex:
not specified

Administration / exposure

Route of administration:
inhalation: vapour
Type of inhalation exposure:
not specified
Vehicle:
air
Details on inhalation exposure:
GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: no data
- Source and rate of air: fresh air
- Method of conditioning air: at room temperature a stream of dried air passed through a fritted disc gas washing bottle containg the test material before it is fed into the exposure apparatus.

TEST ATMOSPHERE
- Brief description of analytical method used: none

VEHICLE
- Composition of vehicle (if applicable): air
- Concentration of test material in vehicle: close to saturation, but unknown as no measurements were made
Analytical verification of test atmosphere concentrations:
no
Duration of exposure:
8 h
Concentrations:
close to saturation at ambient temperature
No. of animals per sex per dose:
6 males
Control animals:
no
Details on study design:
- Duration of observation period following administration: 14 days

Results and discussion

Effect levels
Sex:
male
Dose descriptor:
other: Inhalation Risk Screening Test
Effect level:
ca. 9 mg/L air
Based on:
test mat.
Exp. duration:
8 h
Remarks on result:
other: Estimation of saturation concentration Csat using the genral gas equation, molecular weight and vapour pressure of 2-methylvaleric acid: Csat = 9.53 mg/L
Mortality:
none; 6 of 6 animals survived day 14 post treatment

Any other information on results incl. tables

Estimation of saturation concentration

Starting with the general gas equation (pV = n RT), the number of moles per cubic meter at 20°C will be

n = pV / RT = p 1000L/(83.14 hPa L Mol-1K-1293 K = p 0.041 Mol/hPa.

With the molecular weight this will give the saturation concentration Csat:

Csat [mg/m³) = 41 x MW [g/Mol] x p [hPa].

 

The molecular weight of 2–methylvaleric acid is 116.16 and the vapour pressure (20°C) is 2 hPa (cf. section 4.6). 

This results in a Csat of 9525 mg/m³

Applicant's summary and conclusion

Conclusions:
6 male rats were exposed to a near-saturation atmosphere (9 mg/L estimated) for 8 hours. There was no death at day 14 post treatment.