Calls are mounting for an overhaul of the mainland's safety regulations on chemical plants after another deadly blast on the weekend. An explosion in Zibo, Shandong province, at a plant owned by Shandong Runxing Chemical Technology killed one person and injured nine others late Saturday, less than two weeks after a similar disaster at a chemical warehouse in Tianjin killed 123 people. The Zibo plant and the Tianjin warehouse were less than 1km from residential areas, raising suspicions about safety checks. "The government needs to review the regulations covering the production and transport [of hazardous chemicals], and also the operations of the companies," Greenpeace East Asia campaigner Eric Liu said. Mainland regulations on dangerous chemicals demand a safe distance between storage sites and public facilities, saying that distance must comply with national standards. The State Administration of Work Safety requires there be at least 1km between public facilities and warehouses that are larger than 550 square metres, mainland media reported, raising fears about risks from smaller sites. "Clear and precise definitions of some terms are needed, and the regulations should include some clear indicators for [companies and regulators] to follow," Liu said. The Shandong blast erupted at about 8.56pm on Saturday after a separator at the plant caught fire and exploded. The fire was extinguished at about 2am yesterday. A plant employee died in the blast, authorities in Huantai county, where the plant is located, said yesterday. The Huantai county government said no specific pollutants had been detected and the explosion was under investigation. The Beijing News quoted one man living about a kilometre from the plant as saying that he heard two explosions, which shook his home and broke his kitchen windows. Shandong Runxing Chemical Technology, a wholly-owned subsidiary of Runxing Group, makes chemicals such as adiponitrile, a colorless liquid that can give off toxic fumes after exposed to heat. It is used to make nylon. The plant can produce 100,000 tonnes of adiponitrile a year and started trial output last month. Mainland media reported that it was not uncommon for chemical storage facilities or plants to be close to residential areas. In Pengze county, Jiangxi province, an industrial park that houses 26 chemical companies is close to homes, with the closest plant less than 100 metres away, state-run CCTV reported. Shanghai-based Dragon TV reported that a chemical warehouse in Wuhan , Hubei province, was just one street away from a residential community.