Cleaning, disinfecting, and sterilization in a laboratory have always been of the utmost importance—perhaps even more so in the years following the COVID-19 pandemic. Procedures and results can be easily compromised by interfering residues left in glassware, instrumentation and consumables, and attire. Consult our easy tips below to ensure you operate a clean, safe laboratory.
1. Schedule a regular cleaning time
We schedule everything else in our chaotic work and home life—why not cleaning time, as well? It may seem silly, but having a set, regularly scheduled time to clean—much like a weekly meeting with your boss—will help hold you (and your laboratory) accountable. Cleaning regularly makes your lab both efficient and safe. But it’s not just a basic cleaning that needs to be performed frequently; make a weekly schedule for each area that needs to be washed, including dusting benches, emptying biohazard waste containers used in biosafety cabinets, and any other equipment maintenance that’s needed.
And don’t forget about sterilization needs. Cleaning and sterilizing may go hand-in-hand, but they accomplish two different goals. Cleaning removes inorganic and organic material from laboratory consumables and instrumentation while disinfecting/sterilizing kills microbes that can cause contamination. If debris is not removed via cleaning, it can interfere with microbial inactivation by protecting the microbes, and hence compromise the disinfection and/or sterilization process.
2. Be “sensitive” to the sensitive tools
Some instrumentation and equipment can run for years with a little dusting and some software calibration—but many cannot. When considering cleaning as a whole, be sure to take into account the “special” requirements of sensitive laboratory tools.
For example, laboratory balances are extremely sensitive and vulnerable to accuracy errors from debris or other substances. Thus, keeping your balance clean is critical to obtaining accurate and precise weighing measurements. A good starting point would be to clean the balance after every use or whenever the weighing substance changes. Clean the balance in the following sequence:
1) protect yourself and have the SOP ready;
2) switch off the balance;
3) clean the area around the balance;
4) disassemble removable parts;
5) clean the balance and removable parts;
6) reassemble the balance and switch it on. To protect the balance from dirt and hazardous or sticky substances, use replaceable protective covers. For safe dosing and to avoid accidental spills, use specially designed weighing funnels. When the balance is not in use, use a dust cover to keep it safe.
For laboratory washers, be sure to select the correct detergent. A good manufacturer will provide a detergent selection guide to help identify a suitable detergent based on the type of lab/application, key considerations, and concerns, residuals to be removed, the cleaning method, and/or what articles need to be cleaned/sterilized. Additionally, before making a decision, laboratory managers and analysts should consider the requirements of the College of American Pathology for residue detection method, as well as state and NELAC standards for certificates of analysis and inhibitory residue test reports.
Of course, glassware and instrumentation are not the only elements that need to be cleaned in a laboratory—lab coats and other PPE also need to be free from contamination. Aqueous detergents are suitable for this purpose, especially ones that include dispersants, emulsifiers, and wetting agents to significantly enhance cleaning.
3. Reagents and chemicals
Properly disposing of expired reagents and degraded samples is another part of laboratory cleanliness as they can not only pose a contamination risk but also attract dust and inevitably become clutter. While chemicals are also included in this grouping, their function moves them past cleaning into an even more important topic—safety.
All chemicals should have a label featuring the name, hazard warnings, and date received. High-hazard and time-sensitive materials should have the date opened marked, as well. If it is not labeled it will eventually become an "unknown"—and unknown chemicals pose unpredictable hazards to those who handle the material, and result in higher costs for disposal.
Additionally, careless chemical storage can create high-risk situations. In fact, a 2008 study concluded that chemical accidents stemming from improper storage made up almost 25% of all chemical accidents. A few good, safe rules to live by for chemical storage are:
- All hazardous liquids should be in a secondary container
- Fume hoods are not storage spaces
- Flammable liquids need to be stored in an approved cabinet, or a flammable materials refrigerator/freezer
- Compressed gas cylinders need to be secured
- Solid oxidizers need to be in secondary containers
E.g. potassium permanganate
- Securely close all chemical containers when not in use
- Keep chemicals off the floor