Steady-state column densities of 1017 cm−2 of I(2P3/2) atoms are produced from photodissociation of I2 vapour at 290.5 K using 5 W of 532 nm laser light. Recombination of the I(2P3/2) atoms at the cell walls is minimized by coating the cell surface with a hydrophobic silane (dimethyldichlorosilane/DMDCS). Operation at room temperature, and at an I2 vapour pressure of ~0.2 mbar, without using a buffer gas, allows relatively low Lorentz and Doppler widths of ~2π × 1.5 (FWHM) and ~2π × 150 (HW at 1/e2) Mrad/s, respectively, at the M1 transition of atomic iodine at 1315 nm. These high column densities and low linewidths are favorable for parity nonconservation optical rotation measurements near this M1 transition. Furthermore, as the cell is completely sealed, this method of production of high-density 127I(2P3/2) atoms is also compatible with using iodine radioisotopes, such as for the production of high-density 129I(2P3/2).