[1][4][5] There are now more efficient ways of producing the compound, such as the reduction of ammonium pertechnetate by zinc metal and hydrochloric acid, stannous chloride, hydrazine, hydroxylamine, ascorbic acid,[4] by the hydrolysis of potassium hexachlorotechnate[3] or by the decomposition of ammonium pertechnetate at 700 °C under an inert atmosphere:[1][6][7] All of these methods except the last lead to the formation of the dihydrate.

The most modern method of producing this compound is by the reaction of ammonium pertechnetate with sodium dithionite.

[6] If technetium dioxide is treated with a base, such as sodium hydroxide, it forms the hydroxotechnetate(IV) ion, which is easily oxidized to pertechnetic acid in numerous ways, such as the reaction with alkaline hydrogen peroxide, concentrated nitric acid, bromine, or tetravalent cerium.

This can be a problem if technetium(IV) oxide is released into the soil, as it will increase the solubility.

[2] The molar magnetic susceptibility of TcO2·2H2O was found to be χm = 244×106[clarification needed units].