David Gervais, Chair STAO Safety Chair

STAO’s Safe on Science booklet is a great resource for teachers and is used as the standard for safe practices by many school boards in Ontario. It presently states that only class 1 and 2 lasers should be used in the classroom. This bans almost all laser pointers from your classroom. A recent OAPT Newsletter article questioned why class 3R lasers (most regular laser pointers) are not accepted. After carefully reviewing the literature and holding extensive discussions, STAO has decided that laser class 3R should be added for recommended use in schools. The Safe on Science booklet is being revised and will be completed by March 31. This will be sent to school boards in the province.

Summary: In our readings, it was found that:

• Class 1, 2 and 3R lasers are dangerous in combination with optical instruments which change the beam diameter or power density.
• Lasers used in high school activities do not employ such optical equipment to view the beam.
• For class 1, 2 and 3R lasers with visible beams, the chief protection against eye damage is the natural blink reflex. If a person resists the natural tendency to blink by holding the eyelids open manually when starring into a class 3R laser beam, permanent eye damage will result.
• Direct exposure on the eye by a beam of laser light should always be avoided with any laser, no matter how low the power.
• Class 1, 2 and 3R lasers with visible beams are appropriate for use in high school, particularly in Senior Physics where monochromatic light sources are required. They are also appropriate when teaching grade 10 optics, under close teacher supervision.
• Teachers must ensure that the laser beam is aimed in a safe direction, and that reflective surfaces are arranged so that the reflected beam also travels in a safe direction. This will prevent accidental exposure to the beam.
  

You can and should read the full post here especially if your school or board has been forbidding you to buy and use laser pointers in your classroom.

Editor’s Note: We owe a huge debt of thanks to David Gervais and the STAO safety team for this. You can catch David at the OAPT Conference on Friday May 12. He will be presenting a workshop on Math and Science in House Construction at 9:30 and he will be staffing the STAO table in the exhibit area.

Tags: Light, Safety