Demonstrations are an effective teaching tool. Even though students may not be handling chemicals or using equipment during a demonstration, it is vitally important that instructors follow rigorous safety rules. Continue reading
While serious accidents causing catastrophic injury in high school science activities are rare, when they occur their human toll can be devastating. This post examines one potentially dangerous demo, its hazards and suggestions for safer alternatives.
The Rainbow Flame Demonstration:
Several of the most serious science accidents have resulted from the combustion of flammable liquids in teacher demonstrations like the rainbow flame demonstration. In this demo, metals salts are heated in a ceramic dish containing burning methanol. The flame colour observed is characteristic of the metal. Click on this link for an example of how this demo is sometimes done. Please note that the procedure used in this video, in our opinion, is unsafe, inappropriate for students of any age and NOT recommended for teachers.
Methanol vapours are extremely flammable. Furthermore, since the density of methanol is greater than that or air, methanol vapour can flow invisibly across surfaces like the demonstration desk and onto the floor towards unsuspecting observers. A flame, spark or even a hot surface can supply sufficient energy to ignite the vapour and create a sudden flash fire. The situation can be even more catastrophic if a nearby open container of methanol is present.
The Safer (and Better) Way:
Accidents involving electricity can cause shock, burns, and even death. Reviewing and following a few basic rules will help you improve electrical safety when working with hot plates, electrophoresis equipment, power supplies, Van de Graaff generators, etc. Continue reading
Autoclave, Bleach or Biohazard Bag?
Biology, microbiology and biochemistry labs may generate wastes that must be managed as potentially infectious, biohazardous or regulated medical waste. Continue reading
There’s nothing like the fresh smell of a real tree, but real trees can also pose a serious fire hazard if the tree accidentally dries out. Steve Spangler shares a “television-only” science demonstration with firefighters in a controlled situation that illustrates how dry trees are susceptible to catching fire and ways to avoid this potential fire risk. Continue reading
Lab Glassware Care
Basic Tips for Safety & Savings
Glassware used in research and teaching laboratories is often designed for specific functions. However, the intricate and delicate designs can render glassware easily breakable, reducing durability. For this reason, it’s important that you handle glassware carefully, use it for its intended purpose and inspect glassware for flaws. To prolong the life of your glassware and ensure safety during use, it pays to be aware of three key factors: cleanliness, scratches, and temperature.
Keep it Clean — Good lab technique requires clean glassware.
Note: Be cognizant of leftover chemical residue in your glassware. Water-reactive substances must never come in contact with water.
- Make sure glassware is empty of chemical to its fullest extent and wash as quickly as possible after use. The sooner it is washed, the easier it is to clean. If dirty glassware is not cleaned promptly, built-up chemical residue may be impossible to clean later and may even pose a hazardous situation.
- If immediate cleaning is not possible, soak the glassware in water.
- Use a mild detergent and hot water.
- Grease is best removed in a weak (10% or less) solution of sodium carbonate. Acetone may be used, but take all precautions.
- Additional cleaning suggestions>>
No Scratching — Glass that is scratched is more likely to crack. Don’t use it!
- Metal or glass stirring rods may scratch glass, so use a rubber policeman on the end of your stirring rod or use a plastic stirring rod.
- Avoid using any worn brushes where metal can scratch the glass.
- Use coated or cushioned clamps.
Temperature Tactics — Improper heating and cooling stresses glass.
- Avoid placing hot glass on a cold surface or vice versa.
- When heating beakers with a burner, always use wire gauze with a ceramic center.
- Never heat a glass vessel to dryness over an open flame.
- Do not heat glassware directly on electrical heating elements. Use a hot water bath, oil bath, or heating mantel.
If you have any questions about how to care for laboratory glassware, please contact us. We’d be happy to help.
This Borax controversy is causing me to lose my mind… once again. Continue reading
The document provided below provides general safety rules and procedures that form a strong “backbone” to improve safety in your school.