Environmental Risk Management Program, CanmetMINING, Natural Resources Canada, Ottawa.
Present address: Retired.
Integr Environ Assess Manag. 2018 Jul;14(4):498-508. doi: 10.1002/ieam.4040. Epub 2018 Mar 30.
The transformation/dissolution protocol (T/DP) for metals and sparingly soluble metal compounds was applied to determine the transformation/dissolution (T/D) characteristics of yellow tungsten trioxide, WO ; blue tungsten oxide, WOx, x taken as 2.9; tungsten disulphide, WS ; tungsten metal, W; 3 samples of tungsten carbide, WC; sodium tungstate, Na WO · 2H O; ammonium paratungstate (APT), (NH ) (H W O ) · 4H O; and ammonium metatungstate (AMT) (NH ) (H W O ) · 3H O. The T/D data were used to derive aquatic hazard classification outcomes under the United Nations Globally Harmonized System of Classification and Labelling of Chemicals (UN GHS) and European Union Classification, Labelling and Packaging of Substances and Mixtures (EU CLP) schemes by comparing the data with selected acute and chronic ecotoxicity reference values (ERVs) of 31 and 3.37 mg W/L, respectively. In addition to the concentration of total dissolved tungsten (W), the T/D solutions were analyzed for the concentration of the tungstate anion, because speciation can be an important factor in establishing the ecotoxicity of dissolved metals. Results show that the tungstate anion was the predominant W-bearing species in solution for all substances examined at pH 6 and 8.5. It was found that the 100 mg/L loadings of both the yellow WO and the blue WOx exceeded the 31 mg/L acute ERV, so they would classify as Acute 3-Chronic 3 under the UN GHS scheme but they would not classify under the EU CLP. An effect of pH on the reactivity of the W metal was observed with 3% and 16% W dissolution at pH 6 and 8.5, respectively. Tungsten metal would not classify under either the UN GHS or EU CLP schemes nor would the WS . The WCs were the least reactive in terms of the 1% or less dissolution of the contained W at pH 6. A critical surface area for WC was calculated. The sodium tungstate, APT and the AMT all yielded, at pH 8.5, total dissolved W concentrations that would result in UN GHS Acute 3-Chronic 3 classifications. Integr Environ Assess Manag 2018;14:498-508. © 2018 Her Majesty the Queen in Right of Canada. Integrated Environmental Assessment and Management © 2018 SETAC.
该金属及难溶金属化合物的转化/消解（T/DP）方案被应用于测定黄色三氧化钨（WO ）、蓝色氧化钨（WO x ，x 为 2.9）、二硫化钨（WS ）、金属钨（W）、3 种碳化钨（WC）样品、钨酸钠（Na 2 WO 4 ·2H 2 O）、仲钨酸铵（APT，（NH 4 ） 6 H 2 W 12 O 48 ·4H 2 O）、偏钨酸铵（AMT）（NH 4 ） 10 H 2 W 12 O 48 ·3H 2 O 的转化/消解特性。根据联合国全球化学品统一分类和标签制度（UN GHS）和欧盟物质和混合物分类、标签和包装（EU CLP）方案，将 T/D 数据与分别为 31mg/L 和 3.37mg/L 的选定急性和慢性生态毒性参考值（ERV）进行比较，得出了水生危害分类结果。除总溶解态钨（W）浓度外，还对钨酸盐阴离子浓度进行了分析，因为形态可能是确定溶解态金属生态毒性的一个重要因素。结果表明，在 pH 值为 6 和 8.5 时，所有测试物质溶液中的主要含钨物种均为钨酸盐阴离子。发现黄色 WO 和蓝色 WO x 的 100mg/L 负荷量均超过 31mg/L 的急性 ERV，因此根据 UN GHS 方案，它们将被归类为急性 3-慢性 3，但根据 EU CLP 方案则不会。在 pH 值为 6 和 8.5 时，分别观察到 W 金属的 pH 值对其反应性的影响，W 金属的溶解率分别为 3%和 16%。W 金属既不会根据 UN GHS 或 EU CLP 方案进行分类，WS 也不会。在 pH 值为 6 时，WC 的溶解率小于 1%，反应性最低。计算了 WC 的临界表面积。在 pH 值为 8.5 时，所有测试物质均生成总溶解态 W 浓度，根据 UN GHS 方案，这将导致急性 3-慢性 3 的分类。Integr Environ Assess Manag 2018;14:498-508. © 2018 加拿大女王陛下以其名义。综合环境评估与管理 © 2018 SETAC。
