2-(Thiocyanomethylthio)benzothiazole (TCMTB) is a biocide used in the leather, pulp and paper, and water-treatment industries. TCMTB may enter aquatic ecosystems during its manufacture and use. TCMTB is environmentally unstable; therefore, it is important to evaluate the toxicity of the more persistent degradation products. This study compared the toxicity of TCMTB with its degradation products 2-mercaptobenzothiazole (2-MBT), 2-(methylthio)benzothiazole (MTBT), benzothiazole (BT), and 2-hydroxybenzothiazole (HOBT). Toxicity was determined using Ceriodaphnia dubia 48-hour acute and 7-day chronic test protocols. TCMTB was the most toxic compound evaluated in both the acute and chronic tests with EC50s of 15.3 and 9.64 microg/L, respectively. 2-MBT, the first degradation product, was the second most toxic compound with acute and chronic EC50s of 4.19 and 1.25 mg/L, respectively. The toxicity of MTBT and HOBT were similar with acute EC50s of 12.7 and 15.1 mg/L and chronic EC50s of 6.36 and 8.31 mg/L, respectively. The least toxic compound was BT with acute and chronic EC50s of 24.6 and 54.9 mg/L, respectively. TCMTB was orders of magnitude more toxic than its degradation products. Toxicity data on these benzothiazole degradation products is important because of concerns regarding their release, degradation, persistence, and non-target organism effects in aquatic ecosystems.
One of the major goals of managing the medication of any clinical trial is to ensure that it is distributed effectively. The continued and increasing use of interactive voice response systems (IVRS) in the management of medication has no doubt resulted in savings in terms of optimizing the supply chain. However, as studies become more complex and drug development becomes increasingly expensive, the traditional IVRS system of medication management has had to evolve in response to these increasing demands. As a result, novel methods of IVRS medication management have been developed to provide more flexibility and robustness in the strategies used to manage medication in a bid to further optimize the efficiency of the supply chain.
Skin irritation is a common occupational hazard for employees engaged in the manufacture, transport, and use of industrial chemicals. The most common method used to evaluate dermal irritation and/or corrosion has typically been in vivo tests using rabbits (Draize method). Several in vitro test methods have been developed, with Corrositex being the first to gain approval by a regulatory agency (U.S. Department of Transportation). The purpose of this study was to compare the results of in vitro (Corrositex) assays of dermal irritation/corrosion to in vivo test data for several industrial chemical formulations and to determine the predictability and usefulness of the Corrositex assay for these types of products. Twenty-four (24) formulations were qualified, categorized, and evaluated using the Corrositex method and the results compared to available animal data for each of the formulations. The Corrositex assay accurately predicted a corrosive end point in 8 (57.1%) of the 14 formulations identified as corrosive by the in vivo evaluations. Corrositex accurately predicted a noncorrosive end point for 1 (10%) of 10 formulations determined to be noncorrosive in animal studies. The Corrositex assay overpredicted the packing group for 12 (50%) of the 24 formulations, and underpredicted the packing group for 7 (29.2%) of the 24 formulations. Compared to the in vivo results, Corrositex correctly classified as corrosive or noncorrosive 37.5% of the formulations tested. A concordance of 20.8% for the packing group assignments of the evaluated formulations was calculated. The Corrositex assay did not accurately predict a corrosive end point or packing group assignment for all of the formulations used in this study. Manufacturers should assess the relevance of this method to their products prior to relying on it for compliance with hazardous material and worker safety regulations.
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