Dipropoxymethane

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

13. Aug 1968 - 02. Sep 1968

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1968

Report date:

1968

Materials and methods

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

BASF test - Inhalation Risk Test

GLP compliance:

no

Test type:

other: inhalation risk test

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

1,1'-[methylenebis(oxy)]dibutane

EC Number:

219-909-0

EC Name:

1,1'-[methylenebis(oxy)]dibutane

Cas Number:

2568-90-3

Molecular formula:

C9H20O2

IUPAC Name:

1,1'-[methylenebis(oxy)]dibutane

Test animals

Species:

rat

Sex:

female

Administration / exposure

Route of administration:

inhalation: vapour

Type of inhalation exposure:

not specified

Vehicle:

other: unchanged (no vehicle)

Duration of exposure:

8 h

Concentrations:

11. 24 mg/L (calculated from substance loss)
(calculated saturated vapor concentration: 6.6 mg/l)

No. of animals per sex per dose:

6

Control animals:

not specified

Details on study design:

- Duration of observation period following administration: 7 days
- Frequency of observations: several times on the day of administration, at least once each workday.
- Frequency of weighing: days 0, 7
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight

Results and discussion

Effect levels

Key result

Sex:

female

Dose descriptor:

LC50

Effect level:

> 11.24 mg/L air (nominal)

Based on:

not specified

Exp. duration:

8 h

Remarks on result:

other: Inhalation Risk Test: Substance concentration was calculated from substance loss during the exposure

Mortality:

No mortality occured.

Clinical signs:

other: During the exposure escape attempts, irritation of the mucous membranes and intense respiration. At the end of the exposure period high stepping almost staggering gait, tremor of the whole body. 24 h post application piloerection and calm behaviour

Body weight:

The animals gained weight (no single recording of weight gain).

Gross pathology:

1x bronchial pneumonia (right) and vicariious emphysema (left); 1x chronic bronchitis and bronchiectasis.

Any other information on results incl. tables

The inhalation of a highly saturated vapor-air-mixture at 20 °C caused no mortality after 8 h of exposure.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

No effects were observed in the acute inhalation toxicity studies which warrant classification in accordance with EU Classification, Labelling and Packaging of Substances and Mixtures (CLP) Regulation No. 1272/2008.

Executive summary:

The acute inhalation toxicity studies for Ethylal and Butylal can be used as source data for Propylal. The 4-hr LC50 values for Ethylal and Butylal were estimated to be 4428.7 ppm and 5.62 mg/L, respectively. In order to accurately compare the LC50 values, the values were converted into mg/m³. Notably, for the conversion of ppm to mg/m³ the ideal gas law was used (Annex III). The recalculated LC50 values for Ethylal and Butylal are 19120.38 and 5620 mg/m³, respectively. In terms of bioavailability, Ethylal is considered to be the worst-case, as it has the highest vapour pressure 17000 Pa at 20 °C, compared to a vapour pressure of 111 Pa at 25 °C for Butylal. However, when considering crossing the biological membrane in the lungs, Butylal is expected to be more favourable for absorption in the lungs. Additionally, Butylal has a lower LC50 value and is therefore, the worst-case scenario in this read across. Based on these findings, it is concluded that the target and source substances have similar toxicity potentials via the inhalation route. The read-across is applied with a high level of confidence (AO 5 in accordance with the ECHA RAAF document (2017)).