Rubber products and debris with specific chemical signatures can release their constitutive compounds into the surrounding environment. We investigated the chemical toxicity of different types of new and used rubber products (tires, crumb rubber granulates, aquaculture rubber bands) on early life stages of a model marine organism, Pacific oyster Crassostrea gigas. Leachates obtained from used products were generally less toxic than those from new ones. Leachates from new products induced embryotoxicity at different concentrations: oyster-farming rubber bands (lowest observed effect concentration, LOEC = 1 g L-1) and crumb rubber granulates (LOEC = 1 g L-1) > tires (LOEC = 10 g L-1). Moreover, new oyster-farming rubber bands induced spermiotoxicity at 10 g L-1 (-29% survival) resulting in decreased oyster reproductive output (-17% fertilization yield). Targeted chemical analyses revealed some compounds (2 mineral contaminants, 15 PAHs, 2 PCBs) in leachates, which may have played a role. Rubber used in marine aquaculture (rubber bands) or present at sea as waste (tire, crumb rubber granulates) therefore release hazardous chemical molecules under realistic conditions, which may affect oyster development. Aquaculture development work is necessary to improve practices for eco-safety, as are efforts to limit the contamination of marine environments by terrestrial rubber debris.