The early 1940s saw three major additions to FDA's responsibilities in the drugs area. The Insulin Amendment, passed in 1941, required all batches of insulin to be tested for purity, strength, quality, and identity before marketing. The testing was conducted by a unit in the Pharmacology Division. Also starting in 1941, the agency required prescriber labeling for all new drugs, in concert with the adequate directions for use provision of the 1938 Act. The Penicillin Amendment was passed in 1945, modeled on the Insulin Amendment. The former required batch certification of drugs wholly or partially composed of penicillin. Subsequent amendments extended the certification requirement to other antibiotics. Responsibility for the testing was placed in another separate and independent office, the Division of Penicillin Control and Immunology. Divided into four sections, Penicillin Certification, Immunology, Antiseptics, and Antibiotics, this Division's responsibility extended beyond testing of penicillin. In 1949 the Division was renamed the Division of Antibiotics to reflect the growing scope of functions and antibiotics.