The accident occurred early afternoon at the Futian Chemical Company in Panyu district, Xinhua news agency said, quoting the local government.
Residents were evacuated after "a small amount" of toxic hydrogen chloride gas was detected in the air following the blast, Xinhua said.
Industrial accidents are common in China and people who live close to industrial sites frequently express concern about the effect of hazardous pollutants on their health.
Fourteen workers were killed Saturday in an explosion at a chemical plant in east China. (*)