The United States Center for Disease Control (CDC) has developed guidelines to classify laboratory applications conducted with potentially hazardous biological microorganisms. These levels range from Biosafety Level 1 (the least hazardous) to Biosafety Level 4 (the most hazardous).
In addition to specifying guidelines for the type of work that is classified under each Biosafety Level (BSL), the CDC also has guidelines for the types of precautions and protections needed to mitigate injury resulting from exposure to pathogens. These Biosafety Level protocols have been used by manufacturing companies as references for engineering controls such as biosafety cabinets and glove box enclosures. Creating a secure working environment is a critical goal of the CDC and individual employers.
Controlling microbial contamination is one of the leading concerns in research, clinical, and medical facilities. Microorganisms (hazardous or not) can put personnel, patients and caregivers at risk. In hospital and medical facilities, patients are often immuno-compromised or have serious conditions that make them particularly susceptible to opportunistic microbes or secondary infections.
For these reasons, many products are available for decontamination of these critical spaces. There are differences in product effectiveness, cost, potential residual damage and operational limitations. Two particular methods, presented here, are commonly employed to reduce or eradicate hazardous microorganisms.
Desiccators, sometimes called dry boxes, provide a low-humidity atmosphere for storage of items and materials that would otherwise be damaged by moisture. Desiccators are used for a wide range of applications across several scientific disciplines.
In chemistry and biology, desiccators are often used to store hygroscopic reagents and chemicals. Keeping these compounds in a low-humidity environment drastically increases their shelf life. In semiconductor research and manufacturing, dry storage is often employed to prevent damaging oxidation of wafers and other components that can lead to immediate or latent failures.
Energy comes in many forms. One of those is sound energy, which manifests as vibration. For example, we can hear a loud noise because receptor cells in our ears translate vibrations from sound energy into brain-bound electrical signals. Most sound waves lie outside our range of “hearing,” but produce energy nonetheless. In labs, this ultrasonic energy is used to agitate particles for the purpose of cleaning, mixing solutions, increasing dissolution rate, or to evaporate dissolved gasses from liquids.
Sound travels through air, liquids and solids. The less dense the medium, and the closer the source, the easier the sound waves move. Sound “frequency” is a measure of particle vibration: higher frequencies cause more vibration, and as you can imagine, carry greater strength. Sonicators used in labs are high-frequency instruments that operate at levels above what humans can hear. These ultrasonic waves are above 20 kHz, which is 20,000 cycles per second.
