There were no casualties, but the rocket caused damage to the factory where hazardous chemicals were stored, and resulted in a gas leak of caustic soda.
Police and fire-fighting forces were called to the scene, including teams specializing in handling dangerous materials.
The fire-fighters located the site of the leak, sealed it and cleared the poisonous materials.
Employees working the night shift were at the factory when the rocket hit.
The Home Front Command has cautioned multiple times regarding the storage of hazardous materials in the Sderot and She'ar Hanegev industrial zones, and demanded factories install protective shields.
Only recently have the factories reached an agreement with the army regarding the cost of installing such shields.
The IDF is extremely concerned that since the Hamas takeover of the Gaza Strip, Qassam cells may launch rockets at additional targets in Israel.