The Council of Agriculture (COA) in China announced yesterday that the country’s largest processor of waste copper liquids illegally sold toxic, industrial-grade copper sulfate to at least four livestock feed manufacturers. At least one of those companies did not have a license to produce animal feed in the first place.
They found that industrial heavy metals such as copper sulfate, also known as cupric sulfate, had been mixed with feed for pigs, chickens, ducks and geese which had found its way to farmers all over the country, a practice which could leave heavy metal residues in the animal tissue, the officials said.
Prosecutors said they believe that contaminated livestock and poultry have already entered the market. An official of the Chinese environmental protection agency said if humans eat meat that contains industrial-grade copper, the outcome is “bad to imagine”.
The industrial-grade copper sulfate the company sold was recycled from circuit boards in the electric industry for use in printing ink and batteries. Officials said in one of the four feed processors they found 100 ppm of lead per kilogram in the feed.
The company was raided after the council received a local tip-off last December of an alleged case of improper wastewater treatment for illegally disposing of hazardous waste material. The company processed waste supplied by unlicensed companies and was cited for violating numerous environmental laws for illegally disposing of heavy metal waste into the environment.
Officials are currently investigating the extent and duration the company has been illegally selling industrial waste to feed companies and the number of livestock and poultry that consumed the contaminated feed.
Copper sulfate is a versatile heavy metal that comes in three grades: industrial, agricultural and feed.
Industrial and agricultural formulations of copper sulfate can be cheaper, but industrial-grade copper sulfate is a highly toxic agent that, when ingested, can cause local and systemic damage including coma, shock, severe intravascular hemolysis, hepatotoxicity and acute renal failure with high mortality. The effect copper sulfate on the renal system is kidney abnormalities after copper sulfate ingestion, acute tubular necrosis was observed on urinanylisis and renal biopsy.
In August last year a report surfaced that dioxin contaminated copper sulfate was being sold as a feed additive in Europe. The Rapid Alert System for Feed and Food (RASFF) operated by the EU reported the presence of contaminated of copper sulfate allegedly originating in Romania. This case follows similar instances of dioxin and heavy metal contamination of copper sulfate derived from China. And another in which arsenic was found in copper sulfate sold as a feed additive allegedly originating from Poland.
Generally dioxin contamination of copper sulfate occurs when recycled copper wire is melted to recover elemental copper which is then reacted with sulfuric acid to derive copper sulfate which is incorporated into premixes. In the process of smelting recycled copper wire, plastic insulation is pyrolized and contaminates copper with the degradation products of plastic including dioxins. The maximum level of dioxin in feed is set in the EU at 1ppt (one part per trillion or 1 nanogram/kg).
The most recent episode emphasizes the need for quality control of all ingredients used in diets. Trace quantities of dioxin and PCB/PBB contamination in feed premixes can result in widespread recalls following detection of contaminants in the food chain which is now possible using sensitive and sophisticated analytical equipment operated by regulatory agencies in industrialized nations.
The maximum level for unwanted substances in feed in the EU can be found in the recently updated Directive on Undesirable Substances in Animal Feed (2002/32/EU).
The values for dioxin can be found in Section V of Commission Regulation no. 574/2011.
The dioxin contaminated copper sulphate was distributed to Belarus, Belgium, Dominican Republic, France, Morocco, Netherlands and Syria. More information on the notification can be found in Rapid Alert Safety for Feed and Food (RASFF)