PARENTS have been warned against giving children thermal food containers with glass interiors after fragments from a broken flask injured a schoolgirl. The Consumer Council said yesterday the girl had suffered an eye injury this week when the inner section of her food container cracked and shards of glass spilled out. Council spokesman Kenneth Sau Wai-sang said: 'We have long been concerned about the safety of thermal food containers with glass bulbs for use by children. 'These sort of containers are quite commonly used in Hong Kong for children's school meals. 'But we would advise parents to give their children containers with plastic interiors instead.' In 1990, the Consumer Council carried out impact tests on six models of thermal food containers with inner-glass bulbs. It found that five of them shattered. Mr Sau added: 'We have received complaints about these food containers suddenly shattering. 'It is believed that small cracks in the glass bulb could have developed undetected after a period of use. 'On impact, or after a sudden change of temperature, these cracks in the inner glass could shatter.' The council also warned people who used the containers to avoid putting pressure on the inner-glass bulbs and using metal spoons or forks to get food out of them.