Heat zinc compounds

Heat stabilisers for PVC act by HC1 scavenging and include organotins, mixed metal salt blends, and lead compounds. The latter account for nearly 64 % of volume (in 1994), followed by barium/cadmium and organotin compounds. Cadmium-based heat stabilisers are rapidly being replaced due to environmental concerns. Barium/zinc and calcium/zinc compounds show a high growth rate. It is expected that methyltin stabilisers will soon dominate the growing PVC pipe market. 

Evaporation of a solution produced by dissolving Zn in aqueous hydrochloric acid gives ZnCl2.2H20 as the solid product. Heating this compound does not result in the formation of anhydrous zinc chloride because of the reaction... 

Several people in the 18th and 19th centuries attempted to produce a pure form of zinc oxide for medical purposes. They were unaware that their samples contained cadmium, which at that time was an unknown element. In 1817 Friedrich Strohmeyer (1776—1835), a German chemist, analyzed a zinc compound (calamine) he believed contained zinc oxide (ZnO). However, what he really found was zinc carbonate (ZnCO ), which, though at first unknown to him, contained some cadmium. Strohmeyer then treated his sample with acids until all the zinc was dissolved and thus removed. He then heated the residue with carbon black, resulting in a small ingot of soft, bluish-white metal that proved to be a new element—cadmium. Strohmeyer is given credit for the discovery of cadmium. 

SAFETY PROFILE Confirmed carcinogen with experimental tumorigenic data. When heated to decomposition it emits very toxic fumes of BeO and ZnO. See also BERYLLIUM COMPOUNDS, MANGANESE COMPOUNDS, and ZINC COMPOUNDS. 

CONSENSUS REPORTS Reported in EPA TSCA Inventory. Zinc and its compounds are on the Community Right-To-Know List. SAFETY PROFILE Poison by intraperitoneal route. Moderately toxic by ingestion and subcutaneous routes. Severe irritant to eyes, nose, and throat. Questionable carcinogen with experimental carcinogenic and tumorigenic data. Mutation data reported. When heated to decomposition it emits very toxic fumes of NOx and SOx. See also ZINC COMPOUNDS and CARBAMATES. 

Explosive reaction with alkenes + diiodomethane, sulfur dioxide. Reacts violently with bromine, water, nitro compounds. Ignites on contact with air, ozone, methanol, or hydrazine. Reacts violently with nonmetal halides (e.g., arsenic trichloride or phosphorus trichloride) to produce pyrophoric triethyl arsine or triethyl phosphine. To fight fire, do not use water, foam, or halogenated extinguishing agents. Use dty materials, such as graphite, sand, etc. When heated to decomposition it emits toxic fumes of ZnO. See also ZINC COMPOUNDS. 

SAFETY PROFILE Confirmed carcinogen. Mutation data reported. When heated to decomposition it emits toxic fumes of ZnO and K2O. Used as a corrosion inhibiting pigment and in steel priming. See also CHROMIUM COMPOUNDS and ZINC COMPOUNDS. 

SAFETY PROFILE Poison by ingestion, skin contact, intraperitoneal, and intravenous routes. Moderately toxic by subcutaneous route. An experimental teratogen. Experimental reproductive effects. An eye irritant. When heated to decomposition it emits vety" toxic fumes of NOx, SOx, and ZnO. Used as an antidandruff agent in shampoos. See also ZINC COMPOUNDS and SULFIDES. 

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