Last Revised: January 18, 2022

Revision 4/2020 (original)

Glass is commonly used in laboratories due to its stability, versatility, and flexibility. This Fact Sheet provides some basic guidance for glassware handling in the lab as well as for glassblowing techniques used in laboratories that have training and procedures for those skilled tasks.

Hazard Description

Injuries to the hand are the most frequent occurrence when handling glassware in the lab. Injuries can range from minor, such as cuts, to more serious injuries, such as puncture wounds. Other injuries can also occur as a result of flying glass, chemical exposure, or fire.  

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Basic Glassware Handling

Basic Glassware Handling

The following video from the Dow Lab Safety Academy provides an excellent overview of safe glassware handling procedures. Refer to the various time points listed below for information on specific topics.  

Dow Lab Safety Academy: Glass Handling 

Common Lab Practices 

1:14 – The insertion of glass tubing into a stopper is not a recommended practice 

1:29 – Proper way to insert plastic or rubber tubing onto glass tubing. Example: putting tubing on a condenser 

2:43 – Proper way to handle a hazardous situation such as a frozen joint or stopcock 

Glassware Washing 

3:40 – “Proper Glassware Washing Techniques” 

  1. Wear cut resistant gloves. Add chemical protection too, if needed.  For more information, refer to Penn’s Lab Coat, Gloves, and Safety Eyewear Policy, available here.  
  2. Use protective plastic/rubber matting in and around the sink to prevent glassware from bumping against the sink sides. 
  3. Rest rounded glassware in a cork or rubber ring in the sink. 
  4. Wash one piece at a time so the glass cannot break against other glass in a crowded sink. 
  5. Use brushes with wood or plastic handles/ends to protect glassware from scratches. 
  6. Do not rush. Leave enough time to safely clean glassware.  

Injuries from Broken Glass  

4:40 – Reflexes add to overall risk by increasing the likelihood of getting hurt.  Resist the urge to catch glassware  

4:50 – How to handle injuries from broken glassware 

  1. Turn and walk away from dropped glassware. 
  2. Once safely removed from the accident area, evaluate your medical condition. 
  3. Seek medical attention if necessary. Follow Penn’s emergency response procedures outlined here.  
  4. Alert others in the lab so that they can avoid the broken glass. 
  5. For disposal of broken glass, follow the procedures outlined below. For chemical spill cleanup, follow Penn’s emergency response procedures outlined here

Broken Glass Disposal  

5:32 – “Proper Glassware Disposal Methods” 

  1. Use a proper disposal container designated for broken glass. 
  2. Dispose of clean glassware only. 
  3. Wear appropriate hand and eye protection when handling broken glassware. 
  4. Grasp broken glassware by unbroken sections. 
  5. Drop glassware into the disposal container as gently as possible. 
  6. Never put your hands into the disposal container. 

For more information, refer to the Penn’s Laboratory Glassware/Plasticware Disposal Policy, available here.  


Safe Glassblowing Techniques

Safe Glassblowing Techniques 

The following is a list of safety guidelines for those lab workers conducting glassblowing activities in their lab. Permitted glassblowing jobs are based upon researcher experience. Researchers who complete Karen Carraro’s graduate level “Scientific Glassware” course (Chemistry) will be skilled in common tasks such as unfreezing joints and making port repairs on their manifolds.  

This Fact Sheet contains some important reminders, but it does not replace the need for live demonstration, hands-on training, and supervised practice. 

Approvals and Training 

If you or your lab has not worked with this hazard before and you are considering a procedure that requires you to do so, contact EHRS for guidance. Labs must also contact EHRS before purchasing a torch or burner for the first time and before setting up a glassblowing workstation.  

All work that involves glassblowing techniques requires the approval of the P.I. The P.I. must ensure that the person or team who will be working with the equipment understands the hazards and has received adequate training and supervision for the procedure. Hands-on, in-lab training and supervision is required for inexperienced researchers; in-lab training must be documented.   

Approvals, limits and training pertaining to the use of hazardous gases also applies to any labs using gas torches or burners. For more information, refer to the SOP for Hazardous and Highly Toxic Gases, available here.  

PPE Requirements 

Didymium safety glasses must be worn to filter the bright sodium glare produced when the glass is hated. Wear welder’s goggles when working with Quartz or Vycor glass to filter harmful ultraviolet light produced as the quartz is heated. Wear closed-toed shoes and heat insulated gloves. Avoid wearing synthetic clothing that will burn and melt when exposed to flames or hot glass. Roll up long sleeves to keep them away from the flame. Tie back long hair.  

Heating of Glassware 

Never heat glassware with volatile or toxic materials inside. If you must heat glassware under these conditions, do so in a fume hood with a safety shield. Also attach a trapped blow hose to the glass so that you do not inhale vapors from inside the apparatus.  

After rinsing glassware with solvents, air dry the apparatus to make certain that no solvent remains. Explosions could result otherwise.  

Metal vapors must never be present in glass to be heated. The most common metal encountered in glassware is mercury. Remove all traces of mercury before heating and blowing on this glassware. 

Silicone stopcock grease is another source of contamination in heated glassware. A fine white powder is (silica) is produced when heated to high temperatures. The silica will fire into the glass and in turn, weaken it.  

Conduct a review of sample material processes under vacuum and heat prior to sealing samples under vacuum. Take appropriate precautions, including the use of proper PPE and/or a safety shield, especially when handling condensable gases, volatile materials, or cryogens.  Keep your flame small and avoid over-heating a large area.  

General Best Practices and Tips 

  • Keep your work area clean and free of excess and unused material.  
  • Be aware of all activity in your immediate vicinity. Do not work alone. 
  • Never hand your lab members a hot piece of glassware.  
  • Familiarize yourself with the location of alternative exits and safety equipment in the lab, including safety shower and eye wash.


  1. Dow Lab Safety Academy: Glass Handling
  2. Karen Carraro’s elective Penn course for graduate students titled, “Scientific Glassblowing Course” 
  3. The Scientific Glassblowing Learning Center tutorial