A blaze that started at a pesticide factory in east China's Shandong Province Wednesday caused no pollution, environment authorities said Thursday.

Water and air quality were tested after two explosions and a fire at the Shandong Yanggu Zhongshi Pharmaceutical Co., Ltd. factory in Yanggu County, Liaocheng City, but no contamination was found, said Li Yanfeng, deputy director of the county environment protection bureau.

The bureau deployed more than 20 technicians and eight patrol vehicles to monitor the environment in the area after 8,000 people were evacuated from surrounding villages.

The amount of toxic materials, including benzene, xylene, amine and hydrogen sulfide, in the air did not exceed allowable standards up to a kilometer from the factory, Li said.

A ditch next to the factory had been blocked as it was full of black water with white bubbles.

"The water is waste water from the fire engines. It will be processed after the rescue work," Li said.

The first explosion happened at 5:40 a.m. Wednesday and injured seven people.

The second explosion occurred at 9:30 a.m Thursday and caused a large fireball and thick smoke, as the fire continued to burn after the initial explosion.

Firefighters were unable to extinguish the blaze caused by Wednesday's blast and they were waiting for it to burn itself out when the second explosion occurred.

The flammable chemical, aniline, fueled the second explosion, said a company spokesman.

No casualties from the second explosion were reported.