In this study, we used the model organism Caenorhabditis elegans to evaluate the sublethal toxicity of six F-free AFFF alternatives and a current short-chain AFFF in soil invertebrates. We developed a rapid counting and measuring method for assessing sublethal toxicity in C. elegans. Our group took over the establishment of assays following ISO protocols, the maintenance of the nematodes, and the optimization of the approaches for the extractions of living worms from the soil matrix. The results presented in this publication showed that all tested formulations showed adverse impacts on the growth of C. elegans at concentrations lower than or close to the practical application concentration in the field. Also, five of six F-free alternatives caused reduced reproduction in C. elegans. Formulations containing higher concentrations of hydrocarbon surfactants were more toxic than other formulations to C. elegans. This study provides ecotoxicological data that, combined with data from all related ongoing research, should be used in decision-making regarding recommendations for manufacturing and use of candidate F-free foams.