Teaching Science Safely • Three Teacher Responsibilities • Science Safety References • Physical Hazards • BSC and CHE Safety Measures • Risk Management • Safety Guidelines for Labs, Classrooms, and Storage Areas
Three Teacher Responsibilities(per Council of State Science Supervisors) • Duty of instruction: • Ensure adequate instruction before activity • Identify and clarify risks involved • Provide proper procedures • Duty of supervision: • Misbehavior not tolerated; failure to act problematic • Greater danger requires greater supervision • Never leave students unsupervised • Duty of maintenance: • Maintain safe environment • Maintain safe equipment
NSTA Safety Guidelines Dean, R. A., Dean, M. M., & Motz, L. L. (1978). Safety in the Secondary Science Classroom, Washington, DC: NSTA Subcommittee on Safety.
School Personnel Responsibilities • Principal - general classroom conditions: two exits from lab; appropriate heat and light; burn-resistant tables; master shutoffs on gas, electricity and water; grounded electrical outlets; fume hoods; storage areas; fire extinguishers; shower; etc. • Departmental chairperson - safety meetings; notify principal in writing of safety concerns; safety supplies; safe storage of materials; safety inspections; safety rehearsals; non-accumulation of waste; properly qualified teachers; etc. • Science teacher - instruct students in safety matters; warn students of hazards; develop and use a student safety contract; post safety regulations; provide for required safety materials such as eye protection; care and handling of animals and hazardous materials, proper use of fire extinguishers; safety procedures, etc.
Safety in the Science Classroom • The Safety Program • school personnel safety responsibilities • suggestions for a safe science program • OSHA v. Illinois Life-Safety Code • Safety Procedures (for example) • first aid • eye protection • glassware • health hazards • Laboratory Safety • electronic equipment • rockets, etc.
AAPT Guidelines for Physics Peterson, R. W. (1979). Teaching Physics Safely, Washington, DC: AAPT Committee on Apparatus.
Safety & Physics • Electrical • Lasers and Light • Pressurized & Vacuum Systems • Ionizing Radiation • Fires • Toxic Materials • Mechanical
Electrical • Effects 60 Hz DC • perception: 1 ma 5 ma • loss of control: 10 ma 70 ma • respiratory failure: 25 ma 80 ma • ventricular fibrillation: 100 ma 100 ma • Dry skin resistance • 100,000 to 500,000 ohms / square centimeter • resistance reduced by wetness or sweat • resistance reduced by puncture wounds • Completed circuits to watch out for: • hand to hand • hand to ground
Lasers and Light • Never permits students to look into a direct or specularly reflected laser beam. • Use beam splitters or neutral density filters to reduce the intensity of a laser beam. • Supervise students closely. • Transmission holograms are to be viewed with a beam which is greatly expanded. • Experiments utilizing laser light should not be set up at eye level. • It is preferable to observe projected images rather than looking directly into a laser beam. • Be careful with UV (conjunctivitis).
Pressurized & Vacuum Systems • Gas cylinders must be safely secured and used with a regulator. • Bell jars and coin-feather tubes and prone to implosion. • Never pressurize or evacuate items not designed for such. • Use a clear screen shield and safety glasses to shelter students from harm. Where a screen is not desirable, wrap items with strong tape. • Use high quality dewars, not cheap thermos bottles which might explode from leakage. • Avoid damage due to cold (N2 = -196oC)
Ionizing Radiation • Ionizing radiation consists of alpha, beta, and gamma particles, neutrons, and X rays. • In general: • Quantity -- use the smallest amount avoid direct contact by use of tongs, etc. • Shielding -- a 1-cm layer of Plexiglas will stop high energy beta particles; lead is needed for gamma or X rays • Radiation is endemic, but relatively safe in small doses
Fires • Reduce likelihood of fire. • Watch out for open flames. • Watch out for flash points of liquids and high concentrations in air which might explode. • ethyl alcohol, methyl alcohol, acetone, gasoline, benzene, & carbon disulfide vapors sink and accumulate near floor • Know how to handle types of fires • Class A (wood, paper, cloth) Class B (fats, oils, solvents) Class C (electrical) Class D (metals) • Have emergency materials on hand. • fire blanket or sand • fire extinguisher (ABCD)
Toxic Materials • Solids, liquids, gases: • Mercury, certain metals, asbestos • benzene and carbon tetrachloride • caustic liquids (strong acids and bases) • carbon dioxide and carbon monoxide • Material Safety Data Sheets (MSDS) • Visit the National MSDS Repository: NMSDSR
Mechanical • projectiles • falling objects • moving equipment • powerful permanent magnets
In the event of an accident… • Be prepared with a good safety plan. • Act quickly, correctly, and decisively: • Remove hazard and prevent further harm. • Check with injured party about extent of injury. • Decide on an appropriate course of action. • Notify school authorities and/or call 911 as necessary. • Have properly trained individual care for injured party. • Notify parent, guardian, or designated alternate person. • After event subsides: • Make permanent record of the event • Obtain eyewitness reports • Provide copies to administration • Keep your records in a safe and secure place.
Biology & Chemistry Teaching • As a student in an NSTA-accredited program with broad field preparation you are required to understand the connection between science and safety for all disciplines • You must complete a Legal and Safety Concerns online test at a > 90% performance level. • Read Science and Safety: Making the ConnectionS&S • Here is a brief overview of what you need to know…
Table of Contents (short list) • Where can I find a general science-safety checklist? • How should I label and store chemicals? • How should I purchase new chemicals and dispose of old chemicals? • What should a chemical hygiene checklist for school science labs include? • What precautions should I take when using animals or plants in the laboratory? • What protective equipment should be kept/provided in a laboratory for teacher and student use? • Are there recommended checklists covering the physical layout/specifications of science labs?
Safety & Biological Sciences 1 • Animals - prevent abuse and neglect: • Watch out for student allergies • Handle animals only after proper handling instructions • Gloves and hand washing a good idea • Report bites and scratches • Have vet examine animals that die unexpectedly • Never put fecal matter down the drain • Never use wild animals • Never use poisonous animals • Never allow students to tease animals or touch animals to their mouths.
Safety & Biological Sciences 2 • Plants - many produce toxic substances: • Watch out for student allergies • Never use poisonous or allergy-causing plants in room • Never burn plans that might contain allergy-causing oils • Make a clear distinction between edible and non-edible plants • Never allow plants to be tasted without clear direction from teacher • Have students wear glove or wash hands after handling.
Safety & Chemistry 1 • Labeling chemicals: • Manufacturer or supplier (including address and phone number) • Chemical and/or trade name - same as MSDS • Date received or placed in container • Strength of the chemical • Handling and/or mixing precautions • Appropriate hazard symbol National Fire Protection Association (NFPA) rating
Safety & Chemistry 2 • Storing chemicals: • Keep storage separate from the classroom • Be certain storage area is properly ventilated • Fire door or exits must be provided • Provide for proper extinguishing systems • Shelving must be secured to the wall • Separate organic from inorganic chemicals • Properly separate incompatible chemical families • Make certain chemicals in appropriate containers • Store flammables and corrosives separately
Safety & Chemistry 3 • Acquisition and disposal of chemicals: • Limit acquisitions to needs for 1-2 years • Be certain you can store, use, and dispose of chemical safely before ordering • Be certain you have proper personal protective equipment for working with the chemical • Be certain everyone aware of any hazards associated with chemical • Be certain that everyone who might handle chemical is properly trained to do so • Be certain that budget allows for disposal of chemical and/or any by-products. • Use safe and approved disposal methods
Safety & IL School Law Code • What safety requirements are contained in the Illinois School Law Code to protect persons on school property from injury? • Every student, teacher, and visitor must wear an industrial quality eye protective device when working in chemical or combined chemical-physical laboratories involving caustic or explosive chemicals or hot liquids or solids.
Risk Management 1) Determine the nature of the risks before conducting any potentially hazardous activity. 2) Mitigate potential hazards and damage. 3) Determine what hazards remain. 4) Examine the benefit-to-risk ratio, r. • If r >> 1, then it is prudent to perform the activity in question. • If r <= 1, then it probably is not prudent to perform the activity in question.
Safety Guidelines for Labs • Student Safety Contract: • “Thou shall.... • “Thou shall not.... • Do this during the first day or two of class, but certainly before the first lab • Be prepared with a detailed Safety Plan • A detailed Safety Plan will be required of you for your student teaching site.