Lab Glassware Cleaning: Is Your Glassware Being Cleaned the Right Way?

Preventing cross-contamination and dangerous chemical mixing in a lab requires consistent effort from everyone in the lab. Ensuring glassware is properly cleaned and stored is a simple way to halt data-disrupting contamination events from occurring. However, knowing how to clean lab glassware properly isn’t as easy as straight forward you might think.  

This is because every lab is different. Each has its own focus, specializations, safety protocols, and contamination concerns. For instance, the way a pulp mill’s quality control lab cleans their glassware likely looks very different from a sterile, biomedical lab’s glass cleaning procedures.

 “Washing glassware is relatively simple, however, if not done in accordance with a lab’s processes, compliance requirements, and safety characteristics, it can create havoc for the integrity and productivity of a lab.”

-Olga Vasilikiv, Director of National Laboratory Operations, Pipette.com 

In this article, we’ll explain why cleaning glassware is crucial, how poorly cleaned glassware can impact your lab operations, and tips on how to clean glassware in different laboratory settings.

Why Cleaning Laboratory Glassware is Important

Every experiment and assay in a lab must begin with a clean, contamination-free foundation. This ensures that a lab’s results are trustworthy, reproducible, and often starts with well-cleaned glassware.   

Other reasons why aligned, consistent glassware cleaning processes are a must in any laboratory include:

Accurate Stock Solutions and Reagent Preparation

Stock reagents and solutions are often prepared in glassware, usually in large quantities that are used for several days, weeks, or even months. If prepared in glassware that isn’t clean, or ones that contain contaminants that impact their efficacy, days and weeks worth of data could be put at risk.

Compliance with ISO 4787:2010 and Other Standards

Labs that comply with ISO 4787, or other associated standards, can risk their compliance accreditation if they don’t adhere to the cleaning practices outlined in the relevant standards. Examples of other standards that dictate how to clean glassware include:

• CFR 211.67
• GMP 7
• ASTM D5245-19

Prevent Safety Risks

Accidental mixing of reactive chemicals can lead to dangerous events and even create serious safety risks. Ensuring glassware is thoroughly cleaned mitigates the risk of dangerous reactions, safeguarding both researchers and the lab environment from potential chemical mishaps. 

Prevent Contamination

Preventing contamination is paramount in all labs, but even more so microbiology labs where microbial contaminants can significantly impact research outcomes. Clean glassware prevents the introduction of unwanted microorganisms, which is critical for experiments requiring sterile conditions.

How to Clean Laboratory Glassware: The 5 Basic Steps

As discussed earlier, every laboratory should develop their own best practices for how to clean glassware based on their unique needs, specializations, and compliance requirements. However, there are 5 basic steps that are integral to all methods of cleaning glassware in a lab, which we explain below. 

Inspect glassware for cracks, chips, and other imperfections

Lab glassware from reputable providers is sturdy and can withstand extreme conditions. However, it’s not indestructible. 

A great time to inspect your glassware for cracks, damage, and other signs of stress is before you wash your glassware. If issues are found, set it aside until it can be repaired or disposed of properly. 

Rinse glassware and remove visible contaminants

Start the cleaning process by rinsing your glassware and safely disposing of visible contaminants, if present. Be sure to use the appropriate solvent or rinsing agent and always dispose of the rinse waste in an appropriate, properly labeled waste container. 

This step is crucial as it will prepare your glassware for cleaning. 

Wash glassware

Next, using a laboratory glassware cleaner appropriate to your lab, wash your glassware. Use common dishware cleaning tools such as a washcloth, scrub brush, or other implements. If you clean lab glassware with a dishwasher, be sure to follow the instructions and use only the recommended/outlined detergents. 

If washing by hand, remember to wear the appropriate safety gear. Follow your lab's guidelines on how to rinse your glassware effectively and always dispose of wash and rinse solutions properly.

Sterilization

Labs with sterile environments require an extra step when cleaning lab glassware to ensure the glassware is sterile and safe to use in aseptic conditions. There are a number of methods to sterilize glassware, however, most labs today rely on autoclaves for sterilization. 

Glassware drying

Never dry your glassware by hand. The use of a drying cloth, paper towel, or other cloth could transfer contaminants to your freshly cleaned glassware. Instead, let your glassware air dry on the drying rack, a shelf, or in an approved drying oven. 

Laboratory Glassware Cleaning Tips for Washing Common Chemicals

How you approach cleaning of glassware in a laboratory is largely dependent on the chemicals you work with. Washing out common chemicals from lab glassware involves using specific solvents or cleaning methods suited to the type of chemical.  

For example, water-soluble substances can often be removed with warm water, while organic solvents like ethanol or acetone are effective for organic compounds.  

Acids and bases should be neutralized before washing. Always consult your lab's safety guidelines for specific instructions related to each chemical, as improper handling can lead to safety hazards or damage the glassware. 

Rinse agents for cleaning common chemicals from glassware 

Is Your Lab Glassware Clean? A Simple Test to Use

After following the right steps, procedures, and in-house protocols, you may still be unsure if your lab glassware is clean. A common way to test the cleanliness of your glassware is with the uniform wetting test. 

Uniform wetting is a simple yet effective method for checking the cleanliness of lab glassware; it is done during the washing stage, before sterilization or drying. When glassware is clean, water (or another liquid) should coat its surface evenly without forming droplets.  

This uniform coating occurs because a clean glass surface is free of oils, residues, or any substances that might cause water to bead up or separate. If the glassware is not clean, water will form droplets or not spread uniformly, indicating the presence of contaminants. 

To perform this simple test to check for the cleanliness of lab glassware, follow these steps: 

• Rinse the glassware: After you wash your glassware, rinse the glassware with distilled or deionized water. It's important to use water that doesn't contain any impurities that could affect the test.
• Observe the water coverage: Gently tilt and rotate the glassware, allowing the water to coat its surface. Observe how the water behaves; a clean surface will be uniformly wetted by the water, creating a continuous film without breaking into droplets.
• Check for uniformity: Look for any areas where water beads up or does not adhere smoothly to the surface. These spots indicate the presence of residues or contaminants.
• Wash glassware again if necessary: If you observed any non-uniform wetting, clean the glassware again and repeat the test to ensure it reaches the desired level of cleanliness.

Shop Quality Glassware at Pipette.com

Having good quality glassware in your lab is critical. Glassware that is durable, sturdy, and can withstand harsh chemicals and temperatures is crucial for labs to operate efficiently and safely. 

For the best glassware at affordable prices, visit the Pipette.com website. We sell the top brands you need. You’ll enjoy accessing the essential supplies you need from friendly people you’ll love working with.  

Shop for lab supplies now!