Abstract: Exposure to ultraviolet A (315~400 nm) and B (280~315 nm) from welding arcs is an important risk factor for the development of skin cancer. Based on the concept of net emission coefficient, the radiative properties within the ultraviolet A and B ranges are calculated for argon plasma with a radius of R_p in the temperatures 5 000~25 000 K at atmospheric pressure. The various radiative mechanisms, including continuum (recombination and bremsstrahlung) and line radiation, are considered. It is concluded that although the self-absorption effect is prominent for the entire spectrum, it is very weak for the ultraviolet A and B. When R_p=1 mm, the ultraviolet A and B radiations account for at most of 6.0% and 1.9%, respectively. To the entire spectrum (35~4 500 nm) radiation, and account for at most of 36.5% and 5.0% to non-vacuum-ultraviolet (200~4 500 nm) radiation. This study establishes a theoretical basis for the study of the ultraviolet radiation posed by TIG arcs.