1,3-dimethyl-1,3-diphenylurea

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

april 1976-april 1977

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Comparable guideline study, tested with the source substance Ethyl centralite. According to the ECHA guidance “Practical guide 6" the reliability was changed to RL2 to reflect the fact that this study was conducted on a read-across substance.

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH
1. HYPOTHESIS FOR THE ANALOGUE APPROACH
See attached document in IUCLID Section 13 - RA Justification document.pdf

2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)
See attached document in IUCLID Section 13 - RA Justification document.pdf

3. ANALOGUE APPROACH JUSTIFICATION
See attached document in IUCLID Section 13 - RA Justification document.pdf

4. DATA MATRIX
See attached document in IUCLID Section 13 - RA Justification document.pdf, Table 1: Data matrix

Cross-reference

Cross-reference 1

Reason / purpose for cross-reference:

read-across source

Reference

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

april 1976-april 1977

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Comparable to Guideline study with acceptable restrictions.

Qualifier:

no guideline available

Principles of method if other than guideline:

Toxicology Division Procedural Guide, US Army Environmental Hygiene Agency (USAEHA), 1972

GLP compliance:

not specified

Species:

rat

Sex:

male

Route of administration:

inhalation

Duration of exposure:

8 h

Remarks on duration:

single exposure

Concentrations:

nominal concentration - 0.4, 198 mg/L

No. of animals per sex per dose:

6 males

Control animals:

yes

Details on study design:

- Duration of observation period following administration: 14 days
- Body weight: pre-exposure day, post-exposure day 1, 3 ,7, 11
- Necropsy of survivors performed: yes
- Other examinations performed: body weight,organ-to-body weight ratios weights, histopathology

Sex:

male

Dose descriptor:

LC50

Effect level:

> 198 mg/L air (nominal)

Based on:

test mat.

Exp. duration:

8 h

TEMPERATURE 23°C

Results: Rats exposed to a nominal concentration of 0.4 mg/L for 8 hours showed no toxic signs during exposures and for 14 days thereafter. Body weight gain and organ-to-body weight ratios of the exposed rats compared to the control rats were not significantly different. No exposure related histopathologic changes were noted in tissues and organs.

Interpretation: Compound has a low volatility and should present no acute inhalation hazard from single short term exposure.

TEMPERATURE 50°C

Results: No discernible loss of test material from dispersion tube was found. Rate showed no toxic signs during exposure and 14 days thereafter. Body weight gain and the organ-to-body weight ratios of liver, kidney, lung, spleen and testes from exposed rats compared to the control rats were not significantly different. No exposure related histopathological changes were noted in tissues and organs.

Interpretation: Compound has a low volatility and should present no hazard at room temperature due to the inhalation of ethyl centralite vapors.

TEMPERATURE 100°C

Results: Compound melted and vaporized from dispersion tube into exposure chamber, all compound had been dispersed in 80 minutes at a concentration 198 mg/L. Rats showed no toxic signs during exposure and 14 days thereafter. Body weight gain and the organ-to-body weight ratios of the exposed rats compared to the control rats were not significantly different. No exposure related histopathological changes were noted in tissues and organs.

Interpretation: Vapor presents no acute inhalation hazard from single short term exposure.

Interpretation of results:

practically nontoxic

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

Acute vapor inhalation exposures of rats resulted experimentally in no deleterious effect. These results show that ethyl centralite has a low volatility and should present no hazard due to inhalation ot its vapors at room temperature. Also, if vapors are present, acute inhalation from a single exposure presemts no hazard.

Cross-reference 2

Reason / purpose for cross-reference:

read-across: supporting information

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1977

Materials and methods

Test guideline

Qualifier:

no guideline available

Principles of method if other than guideline:

Toxicology Division Procedural Guide, US Army Environmental Hygiene Agency (USAEHA), 1972

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

1,3-diethyldiphenylurea

EC Number:

201-645-2

EC Name:

1,3-diethyldiphenylurea

Cas Number:

85-98-3

Molecular formula:

C17H20N2O

IUPAC Name:

1,3-diethyl-1,3-diphenylurea

Test material form:

solid: particulate/powder

Details on test material:

- Name of test material (as cited in study report): Ethyl centralite
- Physical state: pulverized white powder
- Lot/batch No.: 1123

Test animals

Species:

rat

Sex:

male

Administration / exposure

Route of administration:

inhalation

Duration of exposure:

8 h

Remarks on duration:

single exposure

Concentrations:

nominal concentration - 0.4, 198 mg/L

No. of animals per sex per dose:

6 males

Control animals:

yes

Details on study design:

- Duration of observation period following administration: 14 days
- Body weight: pre-exposure day, post-exposure day 1, 3 ,7, 11
- Necropsy of survivors performed: yes
- Other examinations performed: body weight,organ-to-body weight ratios weights, histopathology

Results and discussion

Effect levels

Sex:

male

Dose descriptor:

LC50

Effect level:

> 198 mg/L air (nominal)

Based on:

test mat.

Exp. duration:

8 h

Any other information on results incl. tables

TEMPERATURE 23°C

Results: Rats exposed to a nominal concentration of 0.4 mg/L for 8 hours showed no toxic signs during exposures and for 14 days thereafter. Body weight gain and organ-to-body weight ratios of the exposed rats compared to the control rats were not significantly different. No exposure related histopathologic changes were noted in tissues and organs.

Interpretation: Compound has a low volatility and should present no acute inhalation hazard from single short term exposure.

TEMPERATURE 50°C

Results: No discernible loss of test material from dispersion tube was found. Rate showed no toxic signs during exposure and 14 days thereafter. Body weight gain and the organ-to-body weight ratios of liver, kidney, lung, spleen and testes from exposed rats compared to the control rats were not significantly different. No exposure related histopathological changes were noted in tissues and organs.

Interpretation: Compound has a low volatility and should present no hazard at room temperature due to the inhalation of ethyl centralite vapors.

TEMPERATURE 100°C

Results: Compound melted and vaporized from dispersion tube into exposure chamber, all compound had been dispersed in 80 minutes at a concentration 198 mg/L. Rats showed no toxic signs during exposure and 14 days thereafter. Body weight gain and the organ-to-body weight ratios of the exposed rats compared to the control rats were not significantly different. No exposure related histopathological changes were noted in tissues and organs.

Interpretation: Vapor presents no acute inhalation hazard from single short term exposure.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

Acute vapour inhalation exposures of rats resulted experimentally in no deleterious effect. These results show that Ethyl centralite has a low volatility and should present no hazard due to inhalation its vapours at room temperature. Also, if vapours are present, acute inhalation from a single exposure presents no hazard.