In her capacity as Assembly Commissioner for a Sustainable Environment, she was involved in a 2007 row over genetically modified foods in the Welsh Assembly Canteen. The Assembly had earlier signed a document committing to "maximum restrictions on GM crops" when it later became apparent that the Assembly canteen was serving items containing GM ingredients. Barrett explained the situation saying "We have discussed this with our in-house caterers, Charlton House. They do not deliberately source GM foods and in fact make every effort to avoid using GM products."