由于材料的使用性质(化妆品,油漆和其他产品)以及用于潜在风险评估的其他摄入途径的附加安全信息有限。因此,这项研究的目的是获得新型TiO2粉末的安全性数据,根据OECD测试指南(TG408),通过污水处理厂的污泥再循环通过Sprague-Dawley(SD)大鼠的重复剂量毒性产生的GST。根据剂量范围研究的结果(28天重复毒性),GST以0、500、1000和2000mg/kgB.W/天的剂量口服给大鼠90天,并在4周后评估2000mg/kgbw/天的作用的可逆性。在临床症状中,在治疗组(低:第14天或第15天,中:第8天,高:第8天)的所有动物中观察到复合颜色的粪便,并持续观察直至给药结束或恢复期的第1天(高剂量组)。此外,在尸检时观察到治疗组的所有动物的胃肠道中的测试物质滞留和这些器官的内腔中的异物(胃,十二指肠,回肠,盲肠,结肠,直肠)可能表明组织病理学检查中存在测试材料。此外,在详细的临床观察中未发现与测试物质相关的不良反应,感官反应性/功能评估,体重,食物消费,尿路分析,眼科检查,血液学/生化参数,器官重量,组织病理学发现。因此,目前的结果表明,新的TiO2粉末的NOAEL(没有观察到的不利影响水平),在本研究条件下重复口服给药90天后,大鼠的GST被认为是2000mg/kgB.W/天,没有发现目标器官。
TiO2 have been studied on inhalation and skin exposure due to the properties of the materials\' use (cosmetics, paints and other products) and the additional safety information on other intake routes for the potential risk assessment is limited. Therefore, the aim of this study was to obtain safety data for new TiO2 powder, GST produced through sludge recycling of the sewage treatment plant through repeated-dose toxicity in Sprague-Dawley (SD) rats in according to the OECD test guideline (TG 408). Based on the results of the dose-range finding study (28-day repeated toxicity), GST was orally administered to rats at doses of 0, 500, 1000, and 2000 mg/kg B.W/day for 90-day and reversibility of effects of 2000 mg/kg bw/day was assessed after 4 weeks. In clinical signs, compound-colored stool was observed in all animals of treatment group (low: day 14 or 15, middle: day 8, high: day 8) and continuously observed up to the end of administration or day 1 of recovery period (high dose group). Also, the test substance retention in gastro-intestinal tract was observed in all animals of treatment group in gross finding at necropsy and foreign materials in lumen of these organs (stomach, duodenum, ileum, cecum, colon, rectum) likely indicative for the presence of test material in histopathological examination. In addition, no test substance-related adverse effects were noted in the detailed clinical observations, sensory reactivity/ functional assessments, body weight, food consumption, urinary analysis, ophthalmological examination, hematological / biochemical parameters, organ weights, histopathological findings. Therefore, the present results show that the NOAEL (no observed adverse effect level) of new TiO2 powder, GST was considered to be 2000 mg/kg B.W/day in rats after repeated oral administration for 90-day under the present study conditions and no target organs were identified.