By Isabel Reynolds TOKYO, Sept 12 (Reuters) - Tainted rice meant for industrial purposes was served in hospitals and homes for the elderly, the Japanese government said on Friday, prompting a criminal investigation into the food scandal. The scam has unnerved consumers, whose trust in the food industry has been undermined in recent years by repeated quality and false labelling scandals over foods from sweets to meat. "At the moment, there have been no reports of health damage because the density of pesticide residues and mould is low," chief government spokesman Nobutaka Machimura told reporters. "But it is a serious problem that products unfit for consumption were eaten at places like hospitals." He said a criminal complaint had been filed against Mikasa Foods, which has apologised for selling the rice as higher-priced quality grain for food consumption when only industrial purposes such as its use in fertilisers or glue were allowed. The Osaka-based company sold about 700 kg (1,500 lb) of Chinese rice contaminated with higher than permitted levels of organic pesticide methamidophos to catering company Nissin Healthcare Food Service Co, a Nissin spokesman said. It was used in meals served at 119 facilities, including hospitals, nursing homes and one nursery. Mikasa Foods is also suspected of selling as food Vietnamese rice tainted with toxic mould, domestic media said. The scandal has also affected drinks makers, including Asahi Breweries <2502.T>, which was forced to recall 650,000 bottles of shochu, a vodka-like drink, some of which was found to have been manufactured using the contaminated rice. Although Japan generally produces more rice than it consumes, it is obliged to import about 770,000 tonnes a year under international trade agreements. Much of the rice is kept in storage, but some is sold for use in the manufacture of drinks and snacks. The government announced this week new rules to stop the sale of imported rice found to be unfit for consumption. Traders previously had the option of selling such tainted rice for industrial use, but will in future be forced to ship it back. (Additional reporting by Risa Maeda, Editing by Rodney Joyce and Edwina Gibbs)