410.422—Determining total disability: General criteria.
(a)
A determination of total disability due to pneumoconiosis is made in accordance with this section when a miner cannot be presumed to be totally disabled due to pneumoconiosis (or to have been totally disabled due to pneumoconiosis at the time of his death), under the provisions of § 410.418. In addition, when a miner has (or had) a chronic respiratory or pulmonary impairment, a determination of whether or not such impairment is (or was) totally disabling is also made in accordance with this section for purposes of § 410.414(b).
(b)
A determination of total disability may not be made for purposes of this part unless pneumoconiosis is (or is presumed to be) the impairment involved.
(c)
Whether or not the pneumoconiosis in a particular case renders (or rendered) a miner totally disabled, as defined in § 410.412, is determined from all the facts of that case. Primary consideration is given to the medical severity of the individual's pneumoconiosis (see § 410.424 ). Consideration is also given to such other factors as the individual's age, education, and work experience (see § 410.426 ).