 In a 2013 sample conducted by the Johns Hopkins School of Public Health of chicken meat from poultry producers that did not prohibit roxarsone, 70% of the samples in the US had levels which exceeded the safety limits as set by the FDA.The FDA has since revised its stance on safe limits to inorganic arsenic in animal feed by stating that "any new animal drug that contributes to the overall inorganic arsenic burden is of potential concern".Information obtained by the Canadian Integrated Program for Antimicrobial Resistance (CIPARS) "strongly indicates that cephalosporin resistance in humans is moving in lockstep with the use of the drug in poultry production".