7 parts per billion will kill a blue tit, by causing it liver damage and reducing its natural resistance to cold and disease. You won't see it die at the bird table. Peanuts are grown in places such as India, Argentina and Malawi. A batch may be tested and found safe in the country of origin but after being transported, left in containers on quays or in warehouses, could be tested again and found to have lethal levels. There are no U.K. laws relating to safe levels.