Black soldier fly (BSF, Hermetia illucens) larvae is considered one of the insect species with great potential for large-scale production as feed and food. For this to become economically feasible and to contribute to a circular economy, BSF larvae should be reared on substrates with little or no alternative use for feed and food production. One such class of alternative substrate sources consists of former food products. However, BSF larvae may accumulate chemical contaminants from the substrate, which may originate from the foodstuff and/or the packaging materials. This study aimed to investigate the possible presence of chemical contaminants in BSF larvae being reared on former foodstuff substrates at both laboratory and industrial scale. Four experimental treatments were set up: with meat or vegetarian, and containing between 3-6% of either plastic or paperboard carton packaging material. Four-day old BSF larvae were reared for seven days on these substrates. Concentrations of heavy metals, mineral oil hydrocarbons, dioxins and PCBs, and polycyclic aromatic hydrocarbons were determined in the substrate, residual material, and the larvae. Results suggest that BSF larvae can be reared on former food products containing traces of packaging materials, without negative effects on their growth or survival. Bio-accumulation was observed for most of the tested contaminants, in particular for mineral oils and cadmium, which had a bio-accumulation rate of, respectively, about five and 20. However, none of the concentrations of the analysed contaminants in the substrate and the larvae exceeded the respective legal limits in the EU. Results of this pilot study were promising. As a next step, more different former food products should be investigated in future research.