The first of a series of reports recommending Annual Limits for Intakes (ALI's) of radionuclides by workers. This report includes the main text for the whole series of Publication 30, and data on twenty one elements having radioisotopes that are of considerable importance in radiological protection. The actual ALI values in ICRP Publication 30 have become obsolete with the newer dosimetry and dose limits of ICRP Publication 60, and at present the dose coefficients in ICRP Publications 68, 69, 71, and 72 should be used to determine ALI's. However, the vast body of biokinetic information in Publication 30 still forms the basis of much of the calculations underlying those later reports.