Evidence gathered by USDA's Animal and Plant Health Inspection Service and testing by two USDA laboratories has identified LLRice604 as the source of minute levels of regulated genetic material found in Clearfield 131 rice seed.

LLRice604 was developed by Bayer CropScience for herbicide tolerance as part of the LLRice600 series. The protein contained in LLRice604 has a long history of safe use and is present in many deregulated products.

APHIS has deregulated similar genetically engineered herbicide-tolerant products such as corn, canola and soybean.

FDA has evaluated the PAT protein for safety on a number of occasions through the agency's voluntary biotechnology consultation process and has concluded the presence of rice from the LLRice 600 series at low levels in food and feed would pose no food or feed safety concerns. Based on that determination, APHIS will not prevent movement or processing of CL 131 rice from previous years.

In 1999, APHIS deregulated two similar herbicide-tolerant rice lines, LLRice62 and LLRice06. After thorough safety evaluations, APHIS extended this deregulation in November 2006 to include LLRice601.

APHIS has issued emergency action notifications since March 4 to distributors and processors of CL 131 to stop the further distribution and planting of the rice seed. Horizon Ag notified the agency that it believes only 3 acres of CL 131 were planted by a single producer.