Safety, Safety, Safety

By their nature, science demos fizz, pop, bubble, change temperature, produce smoke and sometimes unexpected results. Safety can not be understated. It is paramount that all demonstrations be practiced until the instructor knows exactly what will occur and it is repeatable without error.

Guidelines for successful demonstrations

• Practice your demo.

• Use personal protective equipment (PPE) for you and your students!

• Have students wear safety goggles or use a safety shield if there is the slightest possibility that a container,

its fragments or its contents could be propelled with sufficient force to cause personal injury. A good rule of

thumb is if heat or pressure are involved, audience protection is required.

• Know what you are working with. (Read and understand the SDS.)

• Bigger is NOT always better. Students will always ask for bigger and better, normally does not work well in the end.

• Inspect all equipment and apparatus, especially glassware for cracks or chips.

• Provide for proper ventilation.

• When using a volatile and flammable liquid, keep it covered.

Do not allow it to stand in the open air for any period of time,

especially if it is to be ignited (or if flames will be used nearby).

• Reactions work different when quantities or temperatures are changed.

• Things can go wrong, no matter how well you prepared – make

sure that all necessary safety materials are available.

• Never attempt a demonstration that will place you or your students at risk.

• If heat is involved in the demonstration, make sure all glassware is borosilicate (e.g., Pyrex®) glass and

check for chips and cracks before using.

• If a flammable liquid is used in a demonstration, make sure to cap all reagent bottles after dispensing the

appropriate quantities and be aware of heat sources and flammable vapors. Never repeat a demonstration

using flammable liquids until all containers and surfaces are cool to the touch.

• Use fresh chemicals and clean glassware to prevent possible contamination.

• Always ensure that electrical devices are properly grounded and inspect every electrical circuit before

turning the current on

• Make sure a fire extinguisher is immediately available if there is any possibility of a fire.

• Never pour from bulk containers

• Use small quantities of chemicals and flammable liquids

• Close containers after measuring materials

• Move containers away from the demo

• Repeat any demo from the start – do not try to replenish a reaction in progress

• Small may be better – just project it onto a large screen