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Administrative data

Endpoint:
acute toxicity: inhalation
Type of information:
experimental study
Adequacy of study:
key study
Study period:
04/01/1999 - 03/08/1999
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP, Guideline study: The concentration employed is less than the specified limit concentration of 5mg/L, since 4.09mg/L is the highest technically achievable concentration with a particle size of approximately 5µm (MMAD of 4.74µm)

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1999
Report date:
1999

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to guideline
Guideline:
OECD Guideline 403 (Acute Inhalation Toxicity)
Version / remarks:
(1981)
Deviations:
no
Qualifier:
according to guideline
Guideline:
EU Method B.2 (Acute Toxicity (Inhalation))
Version / remarks:
(1992)
Deviations:
no
Qualifier:
according to guideline
Guideline:
EPA OPPTS 870.1300 (Acute inhalation toxicity)
Version / remarks:
(1998)
Deviations:
no
Qualifier:
according to guideline
Guideline:
other: JMAFF 59 NohSan no. 4200 (1985)
Deviations:
no
GLP compliance:
yes
Test type:
acute toxic class method
Limit test:
yes

Test material

Constituent 1
Chemical structure
Reference substance name:
1-methyl-2-nitro-3-(tetrahydrofuran-3-ylmethyl)guanidine
EC Number:
605-399-0
Cas Number:
165252-70-0
Molecular formula:
C7H14N4O3
IUPAC Name:
1-methyl-2-nitro-3-(tetrahydrofuran-3-ylmethyl)guanidine
Test material form:
solid: particulate/powder
Remarks:
powder

Test animals

Species:
rat
Strain:
other: Crl:WI[Glx/BRL/Han]BR (SPF)
Sex:
male/female
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Age at study initiation: About 12 weeks old
- Weight at study initiation: 321-378 g for males. 188-207 g for females

Administration / exposure

Route of administration:
inhalation: dust
Type of inhalation exposure:
nose only
Vehicle:
air
Details on inhalation exposure:
GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: The exposure equipment comprised a Wright dust feed generator connected to a 40L-exposure chamber utilising a tangential, continuous air-flow system.
Analytical verification of test atmosphere concentrations:
yes
Remarks:
The analytically determined mean achieved atmosphere concentration in the exposure chamber of the treated group was 4.09 mg/L, and MMAD ± GSD of 4.74 ± 2.79 µm. The range of MMAD values obtained is considered to be the minimum attainable.
Duration of exposure:
4 h
Concentrations:
4.09 mg/L
No. of animals per sex per dose:
5 rats per sex per dose
Control animals:
yes
Details on study design:
- Rational for dose level selection: The concentration employed is less than the specified limit concentration of 5mg/L, since 4.09mg/L is the highest technically achievable concentration with a particle size of approximately 5µm (MMAD of 4.74µm).
- Post exposure observation period: 14 days
Statistics:
None

Results and discussion

Effect levels
Key result
Sex:
male/female
Dose descriptor:
LC50
Effect level:
> 4.09 mg/L air
Based on:
test mat.
Exp. duration:
4 h
Mortality:
No deaths occurred during the exposure or observation periods (Table 1).
Clinical signs:
other: No clinical signs of an adverse reaction to treatment occurred during the exposure period and no treatment-related clinical signs of an adverse reaction to treatment were apparent.
Body weight:
Body weight gains were not affected by exposure to dinotefuran (Table 7.2.2-1).
Gross pathology:
Necropsy and post mortem examination did not reveal any treatment-related lesions in either sex. The group mean absolute and relative lung weights of the male treated group were 11 and 14%, respectively, higher than the control group (Table 1). However, the differences are considered to be incidental to treatment with dinotefuran since one control animal had an unusually low lung weight of 1.196g. The lung weights of the treated males were comparable to the lung weights of the other control males.

Any other information on results incl. tables

Table 1: Mortality, bodyweight and lungweight

Sex

Exposure

Mortality

Group mean body weight (g):

Mean lung weight

 

(mg/L)

(dying / tested)

Pre-test

Day 2

Day 8

Day 15

(g)

(%)

Male

0

0 / 5

352

348

356

373

1.68

0.454

 

4.09

0 / 5

342

336

350

366

1.87

0.516

Female

0

0 / 5

197

196

197

204

1.18

0.585

 

4.09

0 / 5

199

198

201

208

1.26

0.614

Applicant's summary and conclusion

Interpretation of results:
practically nontoxic
Remarks:
Migrated information Criteria used for interpretation of results: EU
Conclusions:
The 4-hour inhalation lethal concentration (LC50) value for respirable dinotefuran in male and female rats is > 4.09 mg/L. Although this value falls within the classification category 4, higher concentrations of dinotefuran in the respirable range were not technically feasible after extensive atmosphere development. Since neither clinical signs of toxicity nor deaths occurred at the highest technically achievable concentration, it is considered that dinotefuran does not require classification in the EU according to the CLP regulation.