Except as described in Sec. 150.150, a cargo of hazardous material is incompatible with another cargo listed in Table I if the chemical groups of the two cargoes have an ``X'' where their columns intersect in Figure 1 and are not shown as exceptions in Appendix I. (See also Sec. 150.140.) [CGD 83-047, 50 FR 33038, Aug. 16, 1985]