Abstract: This invention provides heavy-duty cleansers (HDHC), with a high level of biodegradability and little or no ecotoxicity, with a high level of efficiency and a maximum skin tolerance and no systemic toxicity. In the broadest aspect of the invention there is provided a cleansing formulation comprising 5 to 10% of one or more methylesters of vegetable saturated and/or unsaturated fatty acids which may be from several natural sources including sunflower seed oil, soybean oil, rape seed oil, or coconut oil. The formulation includes between about 10% to 30% of one or more surfactants and a preferred combination of surfactants includes at least one ethoxylated fatty alcohol, one alkyl polyoxyethylene glycol, one alkanolamide and one polymeric quaternary ammonium salt.