Flame-Retardant Balloon – Flinn Scientific Canada

Show students a “special” balloon that doesn’t pop when exposed to a flame. Students will come up with very clever ideas for why the balloon doesn’t pop. But, when all is said and done, the “magic” is the result of important scientific principles involving specific heat capacity and heat transfer. Continue reading

A Safer Alternative to the Rainbow Demonstration

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.

The Hazard:

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: 

Click here to download the complete article

STAO Safety Question – Fire Extinguisher Use

fire exting from 123rfQuestion to STAO Safety Committee:

Should teachers be trained on fire extinguisher use?


STAO does not have a position as regards this training, nor is it required by regulation. There are some organizations (National Research Council in their book, Prudent Practices in the Laboratory) that suggest that this training should occur. The decision to train or not rests with the Joint Health and Safety Committee, and the School Board (employer).


Are there any videos that are available for training on the use of fire extinguishers?


Yes. There are several youtube training videos that are available. Some of these are produced by reputable organizations (Fire Training Facilities, Fire Chief Associations, Municipal Fire Departments). STAO does not specifically endorse these videos. The decision to use these rests with the school board (employer) and the Joint Health and Safety Committee.These are three links to videos produced by the Markham Fire Department.The first is specific to maintaining fire extinguishers. (3.5 min long) The second one on the list is specific to their use. It is very short, 44 sec long. The third on the list is captioned and has a commentator that uses American Sign Language to relay the message contained in the captions. It describes fire extinguisher use. (3.5 min)
The link to the video below was produced at a State Fire Training Facility in Arizona. This facility was listed by the Arizona Fire Chiefs Association, affiliated with the National Fire Protection Agency (NFPA). It is detailed, covering fire extinguisher types, and how to use a fire extinguisher.(18.5 min)
We hope that the information contained in this response will help you to decide if Fire Extinguisher training should be included in your school board. If any new information as regards fire extinguishers is discovered as your school board studies this issue, please share that with our Safety Committee. If you have any other safety questions, please do not hesitate to contact our committee at info@stao.org. Feedback as to how useful this information has been, promptness of the response will allow us to improve on this service.
Dave Gervais

Chair STAO Safety Committee

The STAO Safety Committee frequently answers safety-related questions posed by Ontario teachers.

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Guidelines for Safer Demonstrations

stao safety triangleDemonstrations are an integral part of any science program.  These activities engage students and help bring the “real world” into the classroom. STAO has recently developed a collection of safe demonstrations/activities for grades 9 and 10 that have been designed to challenge students’ thinking as well as initiate lively classroom discussions that support constructivist learning. These short demonstrations/activities often involve discrepant events related to the topic of focus in the grades 9 and 10 science curriculum, that may surprise students and that can be observed and/or investigated safely by students in the classroom.  These demonstrations/activities are available for free download at http://stao.ca/res2/demoover.php

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Screening for Safer Chemicals using HMIS


elephant toothpaste

Elephant Toothpaste is a popular demonstration to introduce the concept of decomposition reactions.  The chemical reaction involved is the decomposition of hydrogen peroxide into oxygen gas and water.  The reaction is very slow at room temperature.  Consequently, it requires a catalyst.  Manganese dioxide is commonly used to catalyse the reaction.  However, bakers yeast works just as well, is easier to clean-up and is non-toxic. The key ingredient for this demo is hydrogen peroxide which is readily available in 6% and 30% solutions.  How can you tell whether or not these chemicals are safe to use? Fortunately, most chemicals used in schools come with a HMIS hazard rating. Continue reading