This report summarizes data obtained from chronic feeding experiments using male albino rats. The experiments were started January 18, 1969, and interin reports were submitted April 28, August 16, and October 24, 1949. The period covered was 364 or 385 days. Young rats of the Carworth strain, weighing approximately 70 grams, were assigned at random to each of four groups of 20. One group served as control, one received 200 parts of Santiciser B-16 per million parts of food, one received 2,000 parts per million, and one 20,000 parts per million. The rats were individually housed and received water at all times. The plasticiser was added in the form of the pure compound. Controls received the untreated finely ground commercial dog meal which formed the basis at all diets. Rats were weighed and the amount of food consumed was determined weekly.