The Food and Drug Administration said Friday that it had detained orange juice shipments from Canada after they tested positive for low levels of a banned fungicide previously found in Brazilian juice. The FDA announced earlier this month that it would begin testing foreign orange juice shipments for the presence of the fungicide carbendazim before allowing them to enter the country. On Friday, the agency said that among 80 shipments from around the world it tested so far, six from Canada and five from Brazil had tested positive. The samples that have tested positive so far had carbendazim levels of between 10 and 52 parts per billion. The Environmental Protection Agency says carbendazim levels under 80 parts per billion do not raise safety concerns.