3,4-dihydro-2,5,7,8-tetramethyl-2-(4,8,12-trimethyltridecyl)-2H-benzopyran-6-yl acetate

Endpoint summary

Description of key information

The NOAEL of 500 mg/kg bw/day was based on a well conducted 90-day study in rat comparable to OECD guideline 408 (Abdo, 1986).
The following repeated studies were also part of the assessment for this endpoint: 
28-day studies: BASF (1983);  feed study in rats (OECD 407) and a feed study in dogs (dosing stopped after 28 day in an OECD 409 comparable study ; BASF,1982),  Pfister (1999);  study oral gavage in rats (GLP and OECD 407).
90-day study: Pfannkuch (2000); oral gavage study in minipigs (GLP and OECD 409), supplemented with vitamin K , 
2 -year study : Wheldon (1978); feed study in rats (OECD 453) supplemented with Vitamin K

Key value for chemical safety assessment

Repeated dose toxicity: via oral route - systemic effects

Endpoint conclusion

Dose descriptor:

NOAEL

500 mg/kg bw/day

Additional information

A reliable (GLP, OECD 407) 28 day study in rat (Pfister, DSM;1999) was available . The rats were treated by oral gavage at 180, 600 and 2000 mg/kg bw day. As no treatment-related findings were noted, the NOAEL in this study was set at 2000 mg/kg.

The finding in this study was supported by another 28-day study feed study dogs (BASF; 1982). The dogs were treated at ca. 45, 90, 180 and 360 mg/kg bw/day. The test substance was well tolerated. No clinical signs of toxicity and no deaths were observed. Body weight, food consumption, and clinical chemical, hematological, and urine parameters were not altered. There were no gross/histopathological changes in any group. In this study the NOAEL was set at >360 mg/kg in the dog study.

A 90-day repeated dose (oral gavage) study was available (Abdo et al. 1986). In this study the rats were dosed at 125, 500 and 2000 mg/kg. The relative liver weight was significantly increased in high dose females. Administration of 2000 mg/kg bw/d caused hematological changes: prolongation of prothrombin and activated partial thromboblastin (APTT) times and an increase in fibrinogen value, reticulocytosis and a decrease in hematocrit values and hemoglobin concentrations was observed in males; APTT times were also increased in females. Hemorrhagic diathesis was observed in males and females of the high dose group; and increased medullary erythropoiesis was seen in the spleen of one high dose male.

The test substance at all dose levels tested caused interstitial inflammation and adenomatous hyperplasia of the lung. The lung lesions were observed in all vitamin E-treated groups, and the incidence and severity increased in a dose-dependent manner. These lesions were characterized by increased cellularity, vascular congestion, thickened alveolar walls and the presence of foamy macrophages (some of which had undergone cell death and degeneration) in the alveolar spaces. A lipid-like yellow pigmentation was often present within either the macrophages or alveoli. These effects were attributed (as in the other oral gavage 90-day in minipigs study) to local aspiration of the test substance, which would not occur under normal circumstances. Furthermore, these effects were not seen in the chronic feed study (Wheldon, 1978). Therefore, for the NOAEL derivation the effects in the lungs were not considered.

Because at 500 mg/kg only APTT values were increased in absence of an increase in PT and fibrinogen value, the NOAEL is set at 500 mg/kg.

 

Another reliable (GLP, OECD 409) 90-day study in minipigs (Pfannkuch, DSM; 2000) was available. The minipigs were dosed by oral gavage at 180, 600 and 2000 mg/kg day. In this study prolonged activated partial thromoplastin time was attributed to the suboptimal supplementation of Vitamin K. Also in this study effects in the lungs were seen; macroscopically as firm/grey nodules in the lungs and massive locally extensive to diffuse chronic necrotizing granulomatous pneumonia. These changes were considered to be a local reaction to the aspiration of test substance into the lungs that would not occur under conditions of normal use. Due to the Vitamin K supplementation a NOAEL could not be derived.

 

In a repeated dose toxicity study rats were fed DL-Alpha-Tocopheryl acetate at dietary concentrations providing dosages of 0, 500, 1000 and 2000 mg/kg bw/d for 104 weeks (Wheldon et al., 1983). Vitamin K supplementation suppressed the induced hypoprothrombinemia. Growth rate and survival were unaltered by treatment. The observation of agglomerations of vacuolated macrophages in the hepatic centriacini in all treatment groups, alongside changes in serum liver enzyme activity, suggested a limited hepatic response to vitamin E overload. A NOAEL could not be established, since hemorrhage effects were treated by supplementing Vitamin K after 26 weeks.

 

For the DNEL-derivation a NOAEL of 500 mg/kg bw derived from the 90-day repeated dose study (Abdo, 1986) will be used.

Repeated dose toxicity: via oral route - systemic effects (target organ) cardiovascular / hematological: blood coagulation

Justification for classification or non-classification

According to EU Directive 67/548/EEC and EU Classification, Labelling and Packaging of Substances and Mixtures (CLP) Regulation (EC) No. 1272/2008 classification is not warranted.