The duration of ETO gas sterilization is generally 4 to 72 hours, and the actual duration depends on many factors such as gas concentration, temperature and humidity, loading and material permeability. For instance, for medical devices, in the routine process certified by the US FDA, the pretreatment stage is 4-12 hours (humidity 60%-80%, temperature 40-60 ° C), the sterilization stage is maintained for 4-12 hours (ETO concentration 450-1200mg/L), and the ventilation analysis stage is up to 12-24 hours in order to keep the residue minimal to <1ppm. For example, by installing a fully automated ETO sterilizing unit, Johnson & Johnson reduced the time taken in sterilization of a batch of catheters from 48 hours to 28 hours, translating into a 42% efficiency gain and 150,000 pieces per year increase in manufacturing capacity.
Different industries need to use eto gas sterilization to varying levels. In the pharmaceutical field, sterilizing pharmaceutical packaging materials due to the high material density (1.2g/cm³), a European company needs to extend the sterilization time to 60 hours so that the sterility rate is >10⁶ SAL, but by optimizing the gas diffusion algorithm, the time can be reduced by 18% and the cost can be reduced by 20%. In farming, the Netherlands seed company Bayer used ETO technology to sterilize genetically modified corn seeds, in just four hours (ETO concentration 800mg/L, humidity 55%), from germination rate loss from the standard fumigation process of 15% to 3%.
Technological progress is also minimizing the ETO sterilization cycle. In 2023, the “rapid analysis” technology of a Japanese firm disintegrates ETO residues through nanocatalyzation, reducing the ventilation time from 24 hours to 6 hours, and controlling the residual concentration below 0.3ppm, in accordance with ISO 10993-7 standards. Chinese medical device manufacturer Xinhua Medical’s intelligent sterilization cabinet uses in real-time sensors to measure uniformity of the distribution of gases (error ±5%), narrow down the fluctuation range of sterilization cycle from ±3 hours to ±0.5 hours, and increase the yield rate to 99.8%.
Cost-effectiveness and safety are of top priority. The cost of the conventional ETO gas sterilization is around 300-800 US dollars (equipment depreciation, gas consumption, energy consumption), while the new EU regulation of 2024 requires ETO emission concentrations lower than 5ppm, forcing companies to install new exhaust gas treatment systems and increase investment by 25%. But Steris’ low-dose ETO solution (600mg/L at 37 ° C) has the potential to reduce the cost of a single sterilization to $150 and increase the return on investment (ROI) by 18%.
Cases have proved that improper timing of ETO sterilization is risky. In 2022, a ventilator manufacturer due to inadequate analysis (8 hours only), resulting in high residues of ETO product (1.8ppm detection value), triggering an FDA level 1 recall, and an over-$5 million loss. The study brought forward that the deviation of humidity >10% would increase the failure rate of the sterilization by 12% from 1%, and the time for more than 70% loading to the capacity of the chamber must be increased for more than 50%.
Market trends point that dual solutions to sterilization are being investigated by the medical industry. The “ETO-hydrogen peroxide” combined process of MMM Group in Germany reduces the total cycle from 36 hours to 22 hours with a guaranteed bacteria-killing rate of 99.9999%, which is suitable for the production of emergency surgical instruments. According to Global Market Insights statistics, the global ETO sterilization equipment market will be valued at $1.87 billion in 2023, 35% of which is rapid cycle technology (<24 hours) that saves the medical consumables production cost by 12%.
