Paraffin waxes (Fischer-Tropsch), isomerization

Toxicity to birds

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to birds: dietary toxicity test

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Remarks:

read-across from closely related Gas-to-liquids (GTL) product [covering the low molecular weight fraction of the registration substance, C18-50]

Adequacy of study:

key study

Justification for type of information:

justification for analogue approach: see IUCLID section 13 "Read-across justification"

Reason / purpose for cross-reference:

read-across source

Duration (if not single dose):

5 d

Dose descriptor:

LC50

Effect level:

> 5 000

Conc. / dose based on:

test mat.

Basis for effect:

mortality

Remarks on result:

other: No test item related mortalities and no symptoms were observed within the observation period. At necropsy, no macroscopic findings were observed for the treated animals

Duration (if not single dose):

5 d

Dose descriptor:

NOEC

Effect level:

>= 5 000

Conc. / dose based on:

test mat.

Basis for effect:

other:

Remarks on result:

other: No test item related mortalities and no symptoms were observed within the observation period. At necropsy, no macroscopic findings were observed for the treated animals.

Mortality and sub-lethal effects:

1.1 Mortality
Results of the limit test are presented in Appendix A.

Pre-Test
In the pre-test, the test item was administered to 5 Japanese quails each at dose levels of 200, 1000 and 5000 mg/kg diet. No mortality and no symptoms were observed during a
5-day observation period in all of the dose groups. Therefore, a limit test was performed with a concentration level of 5000 mg/kg diet.

Limit-Test
In the limit test at a concentration level of 5000 mg/kg diet, no mortality of the treated birds was observed within the observation period of 8 days. Therefore, the LC50 level for the test item was > 5000 mg/kg diet.

Three of the 20 control animal died. However, taking into account the 20 control animals of a second study (Harlan Laboratories Study D19794) and 17 reserve animals, in total, only 3 of 57 non-treated animals died during the test period. This is confirmation that the maintenance of the birds was appropriate.


Clinical Signs
Results are presented in the attached Appendix A.

No symptoms were observed at a concentration level of 5000 mg/kg diet. Therefore, the NOEC (no observed effect concentration) was > 5000 mg/kg diet.


Macroscopic Findings
For the Limit test, all animals of groups 1-3 were necropsied at the end of the observation period. The results are presented in the attached Appendix B.
No findings were observed in all the animals necropsied at the end of the study. In one of the control animals that died during the test, inflammatory foci were seen on the outside of the heart. One animal had coagulated blood in the abdominal cavity, probably resulting form the i.p. injection of Esconarkon.


Body Weight
Tabulated body weights are presented in the attached Appendix C.

Average body weights before the start of the treatment ranged from 84.2 to 93.0 g for groups 1 to 3. The body weight of the treated animals was on average 124.6 ± 10.2 g on day 5 and 144.3 ± 11.6 on day 8. These weights were similar to the weights of control groups 1 and 2.


Food Consumption and Test Item Intake
Results are presented in the attached Appendix D.

Individual food consumption

The Individual Food Consumption (IFC) during observation days 0-5 (average values, per animal per day) in group 3 (20.2 g food/animal/day) was similar to the IFC of groups 1 and 2 (17.9-20.3 g) Also after termination of the treatment, the IFC for group 3 (21.1 g) was similar to the control groups (21.0-22.5 g).

Relative food consumption

The Relative Food Consumption (RFC) during observation days 0-5 was 176.1 g (average values, per kg body weight per day) of group 3 (234.1g/kg body weight/day) was similar to the RFC of control group 2 (231.0 g). RFC of group 1 (188.8 g was slightly lower when compared to groups 2 and 3. After termination of the treatment, the relative food consumption of all three groups was similar (169.5-177.4 g).

In conclusion, there was no difference in individual food consumption and relative food consumption between the treated group and the control groups.

Test item intake

The test item intake (TII) was calculated based on the food consumption and the nominal test item concentration in the diet:

Group 3: 1170.6 mg test item per kg body weight per day

The LC50 based on test item intake was therefore > 1170.6 mg per kg body weight per day.

Analysis of Test Item in the Diet

Results are presented in the attached Appendix E.

 

The mean concentration of the substance in the diet samples was 106.9% (see “Results” of the analytical report) of the nominal concentration.

 

Maximal deviation of the homogeneity samples was 8.8% of the mean concentration. Therefore, the test item was found to be homogeneously distributed in the diet. Furthermore, the test item was found to be sufficiently stable in the diet during storage at room temperature for 6 days (average 88.6%).

Schedule

Limit test:

 

Groups	Hatch	Arrival of animals	Start of the limit test	End of the limit test
1-3	28-JAN-2011	08-FEB-2011	14-FEB-2011	22-FEB-2011

Validity criteria fulfilled:

yes

Conclusions:

The median lethal concentration (LC50) for the dietary oral toxicity of the test item GTL base oil ['Distillates (Fischer-Tropsch), heavy, C18-50 - branched, cyclic and linear'] in young Japanese quails was determined as > 5000 mg test item/kg diet.

No test item related mortalities and no symptoms were observed within the observation period. At necropsy, no macroscopic findings were observed for the treated animals. Therefore, the NOEC (no observed effect concentration) was determined as > 5000 mg/kg diet.

Body weights were similar for treated group and the control groups. Food consumption was also similar for the treated group and the control groups.

The LC50 based on test item intake was > 1170.6 mg per kg body weight per day.

Executive summary:

In a dose range finding pre-test, the test item GTL base oil ['Distillates (Fischer-Tropsch), heavy, C18-50 - branched, cyclic and linear'] was administered to 5 Japanese quails each at dietary dose levels of 200, 1000 and 5000 mg/kg diet. All quails survived an observation period of 5 days and no symptoms were observed.

 

Based on the pre-test, a limit test was performed. The test item was administered to one group of 10 Japanese quails by dietary ingestion at a nominal dose level of 5000 mg test item/kg diet for 5 treatment days followed by 3 observation days where the animals obtained basal diet.

 

No mortality was observed in the main study at a dose level of 5000 mg/kg diet, therefore, the LC50 of 'Distillates (Fischer-Tropsch), heavy, C18-50 - branched, cyclic and linear' was determined as > 5000 mg/kg diet.

 

No symptoms and no macroscopic findings were observed in the treated animals. Therefore, the NOEC (no observed effect concentration) was determined as >5000 mg/kg diet.

 

Body weights and food consumption were similar for treated group and the control groups.

 

The mean test item intake over the treatment period of five days was as follows: 

Group	Dietary test item concentration (mg/kg)	IFC g food per animal per day	RFC g per kg body weight per day	TII mg test item per kg body weight per day
1	0	17.9	188.8
2	0	20.3	231.0
3	5000	20.0	234.1	1170.6

IFC:    Individual Food Consumption

RFC:   Relative Food Consumption

TII:      Test Item Intake

 

CONCLUSION

The median lethal concentration (LC50) for the dietary oral toxicity of the test item GTL base oil ['Distillates (Fischer-Tropsch), heavy, C18-50 - branched, cyclic and linear'] in young Japanese quails was determined as > 5000 mg test item/kg diet.  

No test item related mortalities and no symptoms were observed within the observation period. At necropsy, no macroscopic findings were observed for the treated animals. Therefore, the NOEC (no observed effect concentration) was determined as >5000 mg/kg diet.

Body weights were similar for treated group and the control groups. Food consumption was also similar for the treated group and the control groups.

The LC50 based on test item intake was >1170.6 mg per kg body weight per day.

Description of key information

(5d) LC50 >5000 mg/kg diet, OECD 205, GLP on analogue substance 'Distillates (Fischer-Tropsch), heavy, C18-50 - branched, cyclic and linear'

Key value for chemical safety assessment

Short-term EC50 or LC50 for birds:

5 000 mg/kg food

Additional information

Measured toxicity data are not available for the registration substance 'Paraffin waxes (Fischer-Tropsch), isomerization' itself.

An acute avian toxicity study has been conducted with the closely related GTL Base Oil (C18-50; CAS 848301-69-9, EC 482-220-0) in accordance with OECD 205 and GLP.

The acute oral LC₅₀ of GTL Base Oil in Japanese quail was determined to be >5000 mg/kg diet. The NOEC was determined to be ≥5000 mg/kg diet. The LC₅₀ based on test item intake was >1170.6 mg/kg bw/day.

It is concluded that the results are also applicable for the registration substance containing higher molecular weight constituents (C25-C150, about 30-55 % >C50) since hydrocarbons >C50 are expected to be less bioavailable (due to the low water solubility and enhanced size).