2,2,6,6-Tetramethyl-4-hydroxypiperidine was studied for oral toxicity in rats of both sexes in a single dose toxicity test at doses of 0, 592, 769, 1000, 1300, 1690 and 2197 mg/kg. This revealed LD50 values of 1482 mg/kg for males and 1564 mg/kg for females.
2,2,6,6-Tetramethyl-4-hydroxypiperidine was studied for oral toxicity in rats in an OECD combined repeat dose and reproductive/developmental toxicity screening test at doses of 0, 60, 200 and 600 mg/kg/day.
In the repeat dose study, deaths caused by the test substance were observed. This involved one female of the 60 mg/kg group and three males and one female of the 600 mg/kg group. Ptosis of eyelids and mydriasis in the 60 mg/kg or more groups and decreased spontaneous locomotor activity in the 600 mg/kg group were observed in both sexes. Body weight gain was decreased in the 200 mg/kg or more groups and food consumption was increased in the 600 mg/kg group in both sexes. Increases in adrenals weights in both sexes and in liver weights in females receiving 600 mg/kg were also noted.
NOEL for repeat dose toxicity in parent animals in both sexes is considered to be less than 60 mg/kg/day.
In terms of reproductive/developmental toxicity, continuous diestrus was observed in three females of the 600 mg/kg group and the mean estrous cycle of this group showed extension as compared with the control group. With regard to the effects on neonates, viability on day 4 of lactation was decreased in the 600 mg/kg group, and male and female pups of the 600 mg/kg group showed lower body weights on day 4 of lactation.
NOELs for reproductive/developmental toxicity are considered to be 600 mg/kg/day for males, 200 mg/kg/day for females, and 200 mg/kg/day for the F1 generation.
2,2,6,6-Tetramethyl-4-hydroxypiperidine was not mutagenic in Salmonella typhimurium TA100, TA1535, TA98, TA1537 and Escherichia coli WP2 uvrA.
2,2,6,6-Tetramethyl-4-hydroxypiperidine induced structural chromosomal aberrations in CHL/IU cells with 6 hr short-term treatment without an S9 mix. Polyploidy was not induced in any treatment group.
| Purity | : | 99.8 % |
| Test species/strain | : | Rat/Crj:CD(SD) |
| Test method | : | OECD Test Guideline 401 |
| Route | : | Oral(gavage) |
| Doses | : | 0(Vehicle), 592, 769, 1000, 1300, 1690, 2197 mg/kg |
| Number of animals/group | : | Males, 5; females, 5 |
| Vehicle | : | Water for injection |
| GLP | : | Yes |
Test results:
The assessed LD50 values were 1482 mg/kg for males and 1564 mg/kg for females.
| Purity | : | 99.8 % |
| Test species/strains | : | Rat/Crj:CD(SD) |
| Test method | : | OECD Combined Repeat Dose and Reproductive/ Developmental Toxicity Screening Test |
| Route | : | Oral(gavage) |
| Doses | : | 0(Vehicle), 60, 200, 600 mg/kg/day |
| Number of animals/group | : | Males, 12; females, 12 |
| Vehicle | : | Distilled water for injection |
| Administration period | : | Males, 48 days Females, from 14 days before mating to day 3 of lactation |
| Terminal kill | : | Males, day 48 Females, day 4 of lactation |
| GLP | : | Yes |
Test results:
In the repeat dose study, deaths caused by the test substance were observed of a female of the 60 mg/kg group and three males and a female of the 600 mg/kg group. In these animals, necropsy revealed ulceration of the stomach, and small and large intestines in the 600 mg/kg group. In addition, histopathological examination revealed findings expected for ulcers of the stomach and vacuolar degeneration in the tubular epithelium of the kidneys.
Ptosis of eyelids and mydriasis in the 60 mg/kg or more groups and decreased spontaneous locomotor activity in the 600 mg/kg group were observed in both sexes. Body weight gain was decreased in the 200 mg/kg or more groups and food consumption was increased for both sexes of the 600 mg/kg group.
There was no influence of the test substance on hematological or blood chemistry findings for male rats. Increases in adrenal weights in both sexes and in liver weights of females were observed in the 600 mg/kg group. Pathological and histopathological examinations revealed no specific findings attributable to the administration of the test substance in surviving animals.
NOEL for repeat dose toxicity in parent animals in both sexes is considered to be less than 60 mg/kg/day.
<Reproductive and Developmental toxicity>
As for the reproductive ability of parent animals, no effects were detected in males but on estrous cycle examination, continuous diestrus was observed in three females of the 600 mg/kg group and the mean estrous cycle of this group showed extension compared with the control group. There were no effects of the test substance on the copulation or fertility indices. No reasons of the sexual organs were evident on inspection of the pathology of the animals which had not copulated. With regard to the effects on neonates, viability on day 4 of lactation was decreased in the 600 mg/kg group, and male and female pups of the 600 mg/kg group showed lower body weights on day 4 of lactation.
On the basis of these findings, NOELs of 2,2,6,6-tetramethyl-4-hydroxypiperidine for reproductive/developmental toxicity are considered to be 600 mg/kg/day for males, 200 mg/kg/day for females, and 200 mg/kg/day for the F1 generation, respectively.
| Purity | : | 99.8 % |
| Test species/strain | : | Salmonella typhimurium TA100, TA1535, TA98, TA1537, Escherichia coli WP2 uvrA |
| Test method | : | Guidelines for Screening Mutagenicity Testing of Chemicals (Japan) and OECD Guidelines No. 471 and 472 |
| Procedures | : | Pre-incubation method |
| Solvent | : | Distilled water |
| Positive controls | : | -S9 mix; AF-2(TA100, TA98), Sodium azide(TA1535), ENNG(WP2uvrA) and 9-Aminoacridine(TA1537) +S9 mix; 2-Aminoanthracene(all strains) |
| Doses | : | -S9 mix;156, 313, 625, 1250, 2500, 5000 μg/plate +S9 mix;156, 313, 625, 1250, 2500, 5000 μg/plate |
| S9 | : | Rat liver, induced with phenobarbital and 5,6-benzoflavone |
| Plates/test | : | 3 |
| Number of replicates | : | 2 |
| GLP | : | Yes |
Test results:
Genotoxic effects:
S. typhimurium TA100, TA1535, TA98, TA1537
| + | ? | - | |
| Without metabolic activation: | [ ] | [ ] | [*] |
| With metabolic activation: | [ ] | [ ] | [*] |
E. coli WP2 uvrA
| + | ? | - | |
| Without metabolic activation: | [ ] | [ ] | [*] |
| With metabolic activation: | [ ] | [ ] | [*] |
| Purity | : | 99.8 % |
| Type of cell used | : | Chinese hamster lung CHL/IU cells |
| Test method | : | Guidelines for Screening Mutagenicity Testing of Chemicals (Japan) and OECD Guideline No. 473 |
| Solvent | : | JP saline |
| Positive controls | : | -S9 mix, Mitomycin C +S9 mix, Benzo[a]pyrene |
| Doses | : | -S9 mix(24 and 48-hr continuous treatment): 0, 100, 200, 400, 800 μg/mL -S9 mix(6 hr short-term treatment): 0, 100, 200, 400, 800 μg/mL 0, 800, 1000, 1200 μg/mL 0, 1000, 1500, 2000 μg/mL +S9 mix(6 hr short-term treatment): 0, 100, 200, 400, 800 μg/mL |
| S9 | : | Rat liver, induced with phenobarbital and 5,6-benzoflavone |
| Plates/test | : | 2 |
| GLP | : | Yes |
Test results:
Lowest concentration producing cytogenetic effects in vitro:
without metabolic activation(6 hr short-term treatment): 2000 μg/mL(clastogenicity)
Genotoxic effects:
| clastogenicity | polyploidy | |||||
| + | ? | - | + | ? | - | |
| Without metabolic activation: | [*] | [ ] | [ ] | [ ] | [ ] | [*] |
| With metabolic activation: | [ ] | [ ] | [*] | [ ] | [ ] | [*] |
| 1) | The tests were performed by the Biosafety Research Center, Foods, Drugs and Pesticides(An-pyo Center), Japan, 582-2 Shioshinden Arahama, Fukude-cho, Iwata-gun, Shizuoka, 437-1213, Japan. Tel +81-538-58-1266 Fax +81-538-58-1393 |
| 2) | The tests were performed by the Mitsubishi Chemical Safety Institute Ltd., 14 Sunayama, Hasaki-machi, Kashima-gun, Ibaraki, 314-0255, Japan. Tel +81-479-46-2871 Fax +81-479-46-2874 |