Akkadian

milˀu - saltpetre (CAD M₂ 69, AHw. 653)

late (SB, NA) and rare word, doubtedly autochthonous in Akkadian: if at all related to *milḥ-, it is better to be treated as a comparatively late WS (Aramaic?) loanword

PWS

*milḥ- - salt (Fronzaroli 1971: 621, 634, 641; Kogan 2011: 239)

primary noun *milḥ- ‘salt’ is only marginally attested in EthS, cf. perhaps Gez. məlḥ(ā) ‘sapor, judicium, scientia’, extensively discussed in Bulakh 2005c:333‒334