Dry cleaning of medical devices by supercritical CO2

Supercritical CO ₂ (SC): a green solvent for extraction

Used on an industrial scale since the late 1970s for the extraction of natural products in cosmetics, nutraceuticals and the food industry, CO ₂ SC has established itself as an alternative process to conventional solvent-based extraction from the petroleum industry. The first example of large-scale industrialization of this process concerns coffee decaffeination. CO ₂ due to its physico-chemical properties (colorless, odorless, non-toxic, non-flammable) is indeed the most widely used supercritical fluid from an industrial point of view. Moreover, due to its moderate critical conditions (T _c = 31 °C, P _c = 73.8 bar), CO ₂ SC very quickly emerged as a particularly suitable candidate for plant extraction, and in particular as an alternative to organochlorine solvents. It is as dense as a liquid, with gas-like transport properties. It can therefore be used as an apolar solvent to replace much less harmless chemicals (e.g. chloroform, trichloroethylene, perchloroethylene...). Since then, new applications for CO ₂ SC in the cleaning of mechanical and medical parts have confirmed the fluid's potential as an alternative solvent of choice, not only for the removal of hydrophobic residues such as oils, lubricants and monomers, but also for its bactericidal and disinfectant action.

Respect for the environment and regulations (challenges)

Growing interest in environmental issues over the last few years has led to the emergence of innovative solutions that make a definitive commitment to sustainable development, in order to meet requirements in terms of environmental protection, public health and, what's more, to minimize the energy consumption of the processes developed. And above all, beyond the environmental and societal aspects, these processes must be economically profitable to be sustainable. For example, the use of organic solvents for cleaning mechanical parts or medical devices is subject to increasingly stringent restrictions, particularly since the implementation of the REACH directive (ban on the use of trichloroethylene since March 2016), in order to ensure a high level of protection for human health and the environment, against the risks that these chemicals can cause. These constraints are particularly important in the medical industry, so it's essential to offer alternative substances to the organic solvents classically used in cleaning processes. Treatment with supercritical...