The Collaborative International Dictionary of English v.0.48:
light-duty \light-duty\ adj. not designed for heavy or demanding work; as, a light-duty detergent. Opposite of heavy-duty. [WordNet 1.5]WordNet (r) 3.0 (2006):
light-duty adj 1: not designed for heavy work; "a light-duty detergent" [ant: heavy-duty]