Laboratory Sterilization

When working with different types of cells and chemicals, it’s necessary to keep your laboratory sterile to prevent contamination and incorrect results. There are five common ways used to sterilize laboratories: wet heat, dry heat, filtration, solvents, and radiation.

The preferred method is the use of pressurized steam to heat the material being sterilized. This is called autoclaving or using wet heat. Although this method is very effective in killing microbes, spores, viruses and bugs, the steam must reach a pressure of 15 psi at 250˚ F (121˚C) for a minimum of 30 minutes to do so. Wet heat comes with a number of potential problems which include poor heat conductors taking longer to sterilize, deep trays interfering with air removal, double bagged items or tightly stacked loads preventing steam from circulating, just to name a few.

Dry heat is less effective than wet heat taking up to 2-4 hours and needing higher temperatures (320˚-338˚F or 160˚-170˚C) to sterilize. It kills microbes by oxidation of cellular components and required more energy than wet heat.

Filtration does not use heat and is done by putting a solution through a filter with pores too small for microbes to pass through. Filtration cannot be used to kill viruses or phage because they’re able to pass through the pores.

Solvents made with 60-90% water and ethanol or isopropanol can be used as a laboratory disinfectant as well. These solvents are best used to kill microbial cells but will have no effect on spores.

UV radiation is a safe method for sterilizing as it is limited in the amount it penetrates and is best used for small areas. X-ray and gamma rays are another form of radiation which use electromagnets that have damaging effects on DNA. These two types of radiations are far more penetrating which can be more damaging than UV. They are, however, more effective than UV and are effective on large scale plastic items.

With any of these sterilization methods there are many factors that determine how effective the treatment will be: temperature, concentration of the solvents, humidity and exposure time. With so many factors to try to get perfect in order to sterilize your laboratory, wouldn’t it be great to have one method that is full proof, no matter the temperature or conditions?

TOMI^TM’s patented Binary Ionization Technology® (BIT^TM) does just that and is an EPA registered combination solution and application technology, branded as SteraMist^TM, a direct offspring of the Defense Advanced Research Projects Agency (DARPA). BIT is a process that aerosolizes and activates a low concentration of hydrogen peroxide solution that produces a fine aqueous mist which contains a high concentration of Reactive Oxidative Species (ROS). Pathogenic organisms are damaged by ROS through oxidation of unsaturated fatty acids and amino acids which lead to cellular disruption or dysfunction.

The SteraMist^TM Surface Unit enables mold remediation to all surfaces, including sensitive laboratory equipment. The SteraMist^TM Surface Unit is the world’s only fully portable hand-held mold remediation system and achieves consistent control during remediation and has a six log (99.9999%) kill of pathogens, viruses, and spores. The Activated Ionized Hydrogen Peroxide (AIHP) that’s emitted through the SteraMist^TM Surface does not require any wipe down or rinsing and leaves no residue behind and with only 8 minutes needed from application through contact time, and no additional time needed for aeration, laboratory staff can quickly regain access to their space to continue their work.

The SteraMist^TM Environmental Unit can provide complete air and surface mold remediation to sealed spaces of up to 3,663 cubic feet and each applicator can treat up to a 1,221 cubic foot space. Because the SteraMist^TM Environment is remotely controlled, it allows for safe, consistent air and surface mold remediation and can also be configured to treat multiple spaces simultaneously, to help with accidental contaminations in the labs or overnight cleanings. Just like the SteraMist^TM Surface, the SteraMist^TM Environment can achieve a six log (99.9999%) kill of viruses, pathogens, and spores and also has a quick turnaround time of just over 35 minutes from application through aeration time.

ProEx Services is the Factory Sales Representative for TOMI™ Environmental Solutions, Inc., a global bacteria decontamination and infectious disease control company. Contact ProEX today for a quote or more information on validation and EPA certification of the Tomi AiHP sterilization effectiveness.