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Toxicological information

Genetic toxicity: in vivo

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Administrative data

Endpoint:
in vivo mammalian somatic cell study: cytogenicity / erythrocyte micronucleus
Remarks:
Type of genotoxicity: chromosome aberration
Type of information:
migrated information: read-across based on grouping of substances (category approach)
Adequacy of study:
key study
Study period:
No data reported.
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: This study is classified as reliable without restriction because it was carried out according to OECD Guideline 474.

Data source

Reference
Reference Type:
publication
Title:
Unnamed
Year:
1990

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 474 (Mammalian Erythrocyte Micronucleus Test)
Deviations:
no
GLP compliance:
not specified
Type of assay:
micronucleus assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
other: Oily liquid
Details on test material:
SDPO = solvent-extracted, dewaxed paraffin oil. The only details provided about each paraffin oil were the viscosity and percentage of sulphur (presented in a table in the additional methods information).

Test animals

Species:
mouse
Strain:
CD-1
Sex:
male/female
Details on test animals and environmental conditions:
The following data were not provided:
Number of animals dosed per sex
Age of anmials
Environmental conditions of animals

Administration / exposure

Route of administration:
intraperitoneal
Vehicle:
corn oil
Details on exposure:
Test materials were suspended in corn oil and administered by intraperitoneal injection.
Duration of treatment / exposure:
No data reported.
Frequency of treatment:
Single intraperitoneal injection.
Post exposure period:
Bone marrow was harvested at 24, 48, and 72 hours after exposure.
Doses / concentrations
Remarks:
Doses / Concentrations:
1, 2.5, or 5.0 g/kg
Basis:
nominal conc.
No. of animals per sex per dose:
No data provided.
Control animals:
yes, concurrent vehicle
Positive control(s):
Cyclophosphamide in water at 20 mg/kg.

Examinations

Tissues and cell types examined:
Bone marrow cells
Details of tissue and slide preparation:
No data provided.
Evaluation criteria:
No data provided.
Statistics:
No data provided.

Results and discussion

Test results
Sex:
male/female
Genotoxicity:
negative
Toxicity:
no effects
Vehicle controls validity:
valid
Negative controls validity:
valid
Positive controls validity:
valid
Additional information on results:
All but one mouse survived to the scheduled sacrifice, and there was no gross evidence of toxicity.  In only one case was the micronucleus frequency significantly greater than the concurrent negative control.  In this particular case, the negative control was unusually low.  The positive and negative controls responded as expected, confirming the integrity and sensitivity of the assay system.

Any other information on results incl. tables

Table 1. Micronucleus Tests of Mineral Hydrocarbons in Female CD-1 Mice

Sacrifice Time

Dose Level

Sample Number

 

 

1

2

3

4

5

24 Hours

vehicle

0.6±0.9

0.4±0.5

1.8±1.5

1.8±0.8

2.6±1.5

 

1.0 g/kg

2.0±1.6

1.0±1.7

1.2±0.8

1.4±1.1

1.0±1.2

 

2.5 g/kg

1.4±0.5

0.8±0.8

2.6±1.5

1.2±0.8

2.0±0.7

 

5.0 g/kg

0.6±0.9

1.0±1.2

0.8±0.8

0.6±0.5

1.4±9.4

48 Hours

vehicle

0.2±0.4

0.6±0.9

0.8±1.1

1.2±1.3

1.4±1.7

 

1.0 g/kg

0.0±0.0

0.4±0.5

1.6±2.1

2.0±2.9

0.4±0.5

 

2.5 g/kg

0.2±0.4

0.6±0.9

1.0±0.7

2.2±1.3

0.8±0.8

 

5.0 g/kg

1.0±1.4

1.0±0.7

1.0±1.0

1.8±1.3

1.6±1.1

72 Hours

vehicle

1.4±0.5

0.6±0.9

2.0±1.2

0.6±0.5

1.6±0.5

 

1.0 g/kg

0.6±0.9

1.4±1.1

0.2±0.4**

0.6±0.9

0.6±0.9

 

2.5 g/kg

1.0±0.7

0.4±0.5

0.8±0.4**

1.4±0.5

1.8±1.6

 

5.0 g/kg

2.2±1.6

0.6±0.5

1.0±1.0

1.2±1.1

1.8±1.5

Positive Control

20 mg/kg cyclophosphamide

10.8±3.9**

9.2±4.1**

10.4±3.6**

12.8±4.0**

15.8±9.4**

 

**Significantly different from control at p<0.01

Positive control tested at 24 hours only

Table 2. Micronucleus Tests of Mineral Hydrocarbons in Male CD-1 mice

Sacrifice Time

Dose Level

Sample Number

 

 

1

2

3

4

5

24 Hours

vehicle

0.8±0.8

1.6±1.5

4.0±1.6

2.2±0.8

2.6±1.8

 

1.0 g/kg

1.8±1.8

1.6±2.5

3.0±1.4

1.6±1.1

1.4±1.3

 

2.5 g/kg

1.2±1.3

1.2±1.3

0.6±0.5

2.2±0.8

1.4±2.1

 

5.0 g/kg

0.4±0.5

1.8±1.6

2.0±1.9

1.4±0.5

1.8±1.3

48 Hours

vehicle

0.0±0.0

1.0±1.0

1.4±0.5

1.0±0.7

1.6±1.8

 

1.0 g/kg

0.0±0.0

0.8±0.4

1.0±1.0

2.0±1.4

1.4±1.7

 

2.5 g/kg

0.0±0.0

0.4±0.9

0.6±0.5

0.6±0.5

1.0±0.7

 

5.0 g/kg

1.6±1.3**

0.6±0.9

0.8±0.8

1.4±1.3

1.8±0.8

72 Hours

vehicle

0.8±0.8

0.6±0.5

1.2±1.3

2.0±1.1

0.8±0.8

 

1.0 g/kg

1.0±1.2

0.8±0.8

1.2±0.8

0.4±0.9

1.4±1.7

 

2.5 g/kg

2.0±1.6

0.4±0.5

1.0±1.2

1.0±1.7

0.8±0.8

 

5.0 g/kg

1.4±0.5

0.6±0.5

0.6±0.5

0.8±0.8

1.0±1.2

Positive Control

20 mg/kg cyclophosphamide

12.2±5.6**

7.2±3.8**

11.0±6.7**

12.0±2.9**

17.4±5.0**

**Significantly different from control at p<0.01

Positive control tested at 24 hours only

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information): negative
The five mineral hydrocarbons tested in the mouse micronucleus assay were not clastogenic.
IP346 data were not available for these samples. Accordingly it was not possible to differentiate them on the basis of IP 346 levels. However, as described in the report on unrefined and acid treated oils (CONCAWE, 2007), a distillate aromatic extract was not active when tested in this assay. Accordingly, if the aromatic constituents of these oils are not active when tested separately, it seems reasonable to assume that none of the oils in the lubricant base oil category would be active in bone marrow assays for chromosomal mutations.
Executive summary:

In a CD-1 mouse bone marrow micronucleus assay, male and female mice were given a single intraperitoneal injection of 5 different paraffin oils in corn oil vehicle at doses of 0, 1.0, 2.5, or 5.0 g/kg.  Bone marrow cells were harvested at 24, 48, and 72 hours post-dosing.  One animal did not survive to scheduled sacrifice, but there were no gross signs of toxicity.  The micronucleus frequency was significantly greater than the concurrent negative control in bone marrow cells of male mice given 5.0 g/kg at 48 hours post-dosing, but the negative control was unusually low in this instance, and therefore this result is not considered significant.

This study received a Klimisch score of 1 and is considered reliable without restriction because it was carried out according to OECD Guideline 474.