A decommissioned World War II-era US warship was blocked from leaving a California shipyard for China by the US Environmental Protection Agency (EPA), which said the ship was contaminated with toxic chemicals known as PCBs. The ship was to be scrapped in China before its owner Sanship Inc was blocked by the EPA, acting on information from environmental groups. The ship had PCB contamination of 125,000 parts per million ? the US Toxic Substances Control Act forbids export of materials with a PCB concentration of higher than 50 parts per million. PCBs were banned in the US in 1978.