Salisbury Health Care trust has apologised for not making it clear to plastic surgery patients that their surplus skin would be sold for chemical weapons research.The trust sold skin removed during breast and abdominal surgery to the Defence Evaluation and Research Agency at Porton Down for £17,000 a year.The trust has decided to stop providing skin to the agency in the light of issues raised in the Alder Hey report.In a statement, it apologised to patients for the fact that patient consent forms had not specified the exact use of the skin.