Darla McFarren

Classroom Safety Plan

Classroom Management & Organization

Spring 2001

"‘Nothing in life is to be feared: It is only to be understood.’ – Madame Curie" (Fawcett, 1).

Madame Curie tells us that we need to understand our experiences, which easily transfer over to the lab. Many times science students and science teachers are afraid in the classroom, particularly in chemistry class. if they don’t understand the importance of safety, students and teachers really should fear the potential of safety hazards that are found in the high school lab.

There are many reasons that safety practices should be implemented into the classroom. Not only is the teacher concerned about the students’ health in a genuine caring capacity, but he/she also may be liable for accidents that happen in the laboratory which could have been prevented or foreseen.

Pure accidents are defined as being injuries or mishaps which could not be avoided by precautions, however the line between pure accidents and teacher’s negligence can be thin (NEA, 10). "Negligence is the conduct below a standard established by law for the protection of others against the risk of harm" (NEA, 10). In other words, if a teacher conduct is the primary cause of the student injury, and there is no rule that dismisses teacher liability, then the teacher is the legal cause of the injury and will be held liable (NEA, 11).

Teacher conduct may be the cause of injury if there are preventative measures that can be taken by the teacher to stop the injury from occurring. Most injuries happen because of improper supervision or instruction in the lab (NEA, 32). A teacher is only not liable when the accident could not be foreseen, or the teacher couldn’t exercise any control over the situation. Many of the accidents can be prevented with proper safety practices. A Laboratory Safety Plan should be in place as a preventative measure for most accidents.

The best choice for all involved is for the teacher and students to be prepared for what happens in the laboratory classroom. Prevention now is better than regret later.

Identifying the hazards that are present in the lab and the types of accidents that occur from those hazards is a good place to start with laboratory safety. Common hazards that are found in the lab could be broken down into different types of hazards. Hazard categories and common substances found in those categories follow:

• Corrosive hazards

• Reactive hazards

• Insidious Hazards

• Toxic Hazards

• Biological Hazards

• Physical Hazards

A teacher who is working in a field that has high potential to experience these hazards needs to have training to be able to handle these specific hazards which are present in the lab.

The first step in teacher training is to get certified in first aid or CPR to be eligible to administer emergency first aid to the students who need medical attention. The teacher must be trained on safety devices, such as the eyewash, fire extinguishers, safety showers.

The teacher should then note the evacuation routes in the event of an emergency, and have a list of current emergency phone numbers available for use. The teacher must know the location of every fire extinguisher, fire blanket, fire alarm, and other safety items to help in an emergency. This should coincide with the school safety plan that has been drafted by other teachers and committees in the school.

The teacher should also know about labels on chemicals that are used in the lab. There may be several different types of labels that all convey hazard information. A good label will have these main parts:

• identity of chemical
• danger / warning / cautions
• statement of hazards
• precautionary measures
• first aid instructions
• antidote (if there is one)
• fire spill emergency instructions
• container handling and storage instructions (Young, 35)

Common labels include labels by OSHA (Occupational Safety Hazard Association), DOT (Department of Transportation), HMIS (Hazardous Material Identification System) NFPA (National Fire Protection Association). One can also find data about chemicals being used in the MSDS (Materials Safety Data Sheets) which help inform about the same information.

All hazardous chemicals should contain a label of some format. If a label is not present, then the teacher must find the MSDS for that chemical. If there is no label to find the identity of the substance anywhere, the teacher must not use the chemical in the classroom, or store it, the teacher should dispose of the chemical. Unlabeled chemicals can often be a large safety hazard in the classroom.

OSHA codes are the most general compared to the other common labels. Some characteristics of OSHA labels are:

• Has identity code
• Hazard warning for some hazards
• Name and address for emergencies

DOT labels are found only on the outside of packages when then chemicals are being transported. Some characteristics of DOT labels are:

• Diamond Shaped
• Transporting hazard information only
• Found only on outer packaging

HMIS and NFPA labels are similar in the colors and scale that is used on the labels. Both designate blue as health, red as flammability, and yellow as reactivity, and use a scale of 0-4 (0 being least dangerous, 4 being most dangerous) to show at a quick glance how to identify the chemical inside. HMIS labels also include:

• Chemical identity
• Describes the nature and degree of potential hazard
• Recommended personal protective equipment
• Any chronic health effects (Young, 35)

NFPA labels are intended to be used in conjunction with other labels. The NFPA system is the visual label that allows users to see the overall properties of the chemical inside. A typical NFPA label would show:

3 Can cause serious injury despite medical treatment.

2 Can cause injury. Requires prompt treatment.

1 Can cause irritation if not treated.

0 No hazard.

4 Readily detonates or explodes.

3 Can detonate or explode but requires strong initiating force or heating under confinement.

2 Normally unstable but will not detonate.

1 Normally stable. Unstable at high temperature and pressure. Reacts with water.

0 Normally stable. Not reactive with water.

3 Can be ignited at all normal temperatures.

2 Ignites if moderately heated.

1 Ignites after considerable preheating.

0 Will not burn.

C - may be carcinogenic upon chronic exposure

Cor ­ corrosive

Exp ­ risk of explosion

Oxy ­ oxidizing agent

SC ­ suspected carcinogen

T ­ toxic

W ­ water reactive

Pol ­ polymerizes under normal conditions

Materials Safety Data Sheets can be found about any chemical that poses a hazard or a risk in the lab. MSDS) must be supplied with hazardous chemicals and may be requested for other chemicals. Teachers and students should be familiar with the type of information contained on a MSDS and be able to interpret the sheets from a variety of chemical suppliers. Although the numbering of sections and the order of appearance may differ from supplier to supplier, the following must be on each MSDS:

An MSDS that is filled out for Sodium Hydroxide is on the following two pages.

Fires are one of the most common hazards of the labs, so a teacher must know the different types of fire, and how to use the fire extinguishers.

To identify the needs of a fire, the fire triangle used to be used to describe those needs. Now, we use a fire square to show what a fire needs.

Chain reaction

Ignition Oxidizer

energy

Fuel

By taking away any side of the fire square, the fire can be extinguished (Fawcett, 40). Fire extinguishers will often times have a label that designates the class of fire that they are best suited to extinguish. Different types of fire extinguishers should not be used for fires that it is not suited for. In this case, the fire may become more out of control instead of becoming under control.

Fires and Fire Extinguishers (Manitoba, Chapter 8)

Class A ­ Fires involving ordinary * Use water (dry chemical extinguisher can also be used)

combustible materials such as

wood, cloth, paper

Class B ­ Fires involving flammable * Dry chemical foam, CO2

liquids such as solvents, greases,

gasoline, and oil

Class C ­ Fires involving electrical * Non-conducting agents (e.g., dry chemical or carbon

equipment dioxide)

Class D ­ Fires involving combustible * Special dry powder medium or dry sand.

metals such as magnesium, sodium,

lithium, powdered zinc

To ensure maximum use from a fire extinguisher, the teacher should know the locations of these fire extinguishers and must insure that the fire extinguishers follow these guidelines

Fire Extinguisher Location and Condition must be:

• maintained in operable condition and completely checked at least annually
• recharged after every use
• marked clearly as to class and use
• located conspicuously and marked with signs
• mounted at an accessible height, preferably near an exit door or near the area of use
• checked monthly

Fire has always been one of the attendant hazards of laboratory operation. Laboratories make use of flammable materials including solids, liquids, and gases. Common sources of fire hazards in school laboratories are:

Every school laboratory should be equipped with firefighting devices including

• a fire blanket (made of fire-proofed wool/rayon material or woven fiberglass) not to be used where spillage and fire spreading is
• possible, mounted low enough so it can be reached by a person lying on the floor
• a sand bucket and scoop ­- useful for small fires of all kinds
• an adequate number of suitable fire extinguishers
• teachers trained in the correct use of the appropriate equipment

Dealing With a Small Fire

• ask all students to keep away immediately (the teacher alone should deal with any fire)
• leave to burn out if only a small amount remains to burn and flames are unlikely to ignite other materials
• wear a face shield, heat-resistant gloves, and place a fire-resistant cover over the fire if more than a small amount remains to burn
• (avoid breathing fumes) (Manitoba, Chapter 8).

A teacher should be able to minimize the hazards in the lab by remembering to play it safe. A few general guidelines for a teacher are:

A major part of an accident prevention program is the ability to teach this program to your students to let them know about the seriousness of safety, and show them the procedures they are supposed to follow to help prevent accidents.

Talking about correct safety procedures in lab is not enough. Active demonstrations should occur to help the students know how to use the safety equipment in the lab. Running the eyewash station and having a poster that says "15 minutes of water for that open eye" could be a reminder for students to use the eyewash correctly. The shower station should be shown how to be used as well.

The teacher should be trained in teaching the students about fire extinguishers, or the teacher should get the fire department to come and talk to the students about fires. The students should practice at aiming at the base of the fire, walking up to the fire and not splashing into it with the fire extinguishers. Students need to remember the methods of stop, drop, and roll.

Students in the lab should also be warned that water may not be appropriate to put out many of the fires in the lab. In the lab, the students will not expect water to become an oxidizing agent for the fire, but in the case of some chemical fires where a CO2 extinguisher is needed, the use of water to put out a fire could become more hazardous.

Students should also be taught how to handle themselves in an accident. Even when the teacher is not a medical professional, specific types of accident treatments could be used by the teacher or the student, depending upon the severity of the accident. A general reminder of how to treat minor injuries include:

• Burns should be submerged under cold water,
• cuts should be washed with soap for a few minutes,
• If acid is spilled on clothes, they should be taken to the shower and removed under the shower
• If chemical is in the eyes, they should wash for 15 minutes at the eyewash, keeping their eyes open
• They should stop, drop & roll if they are on fire
• Students should not be in charge of putting out the fire (Safety Course)

Students should be taught the importance of communication in a science lab. The students should tell the teacher if they have contacts or allergies, medical devices, and special needs (extra hearing aids). They should stress the need for reporting accidents immediately and for watching out for each other’s safety (Manitoba, Chapter 2).

The students should also be held accountable for knowing the safety procedures by making it a part of the grade for the class through practice sessions, and lab quiz questions.

Students should know, what to do, how to do it, where the items are located to help, and become familiar with the chain of events before it is necessary to know.

It also is important to teach students how to clean up in the lab to insure safety of the next lab group and themselves once they leave the lab. Teaching students to wash up to their elbows any time they have encountered a chemical other than water is a good practice to make sure that the student’s arms do not react with chemicals encountered outside of the lab. Reminding students of the dangers may help their cooperation with this.

Cleaning up the lab equipment is also essential for a clean and safe laboratory. The glassware that is used should be rinsed out with soap and water to make sure that chemicals are not lingering around after the class is done with their experiments. Clean tabletops also are important to prevent the mixing of unwanted chemicals on the tables.

Finally, students must be taught how to handle the Bunsen burner. A student must know what direction the shut off valve must be for the gas to flow in a Bunsen burner, so they can shut off the burner before too much gas has entered into the room. The student must practice the idea of turning on the gas after the match has been lit, or using the striker immediately after the gas has been turned on. Minimizing the amount of time between the gas entering the room and the burner being lit (a lit burner burns off the gas and prevents gas from entering the room) can minimize the chance of an unwanted explosion in the classroom.

Using some prevention practices in the lab can prevent many lab injuries. A list of do’s and dont’s can explain good and bad practices in the lab.

• Make certain students know the nature of the experiment and dangers involved
• Give careful instructions of equipment usage and materials used
• Give proper supervision of classroom experiments
• Package, store and label chemicals properly
• Control student access to the supply room
• Keep highly toxic chemicals under lock and key
• Wear eye protection at all times
• Wear appropriate clothing for corrosive, toxic or flammable materials
• Know where safety equipment is located
• Watch others in lab and tell them if something is dangerous
• Wash hands and equipment before leaving the lab
• Check on safety equipment regularly
• Inventory the things in the lab
• Analyze accidents to help prevent new ones
• Eliminate the causes of close calls
• Inform others of your intentions
• Have regularly scheduled fire drills
• Have someone be in charge of taking a head count in evacuation
• Designate a meeting place for evacuation
• Inform others of the escape route, and an alternate route
• Know how to administer first aid / CPR
• Use appropriate disposal containers
• Use small amounts of chemicals
• Check hoods for proper air flow
• Insure that eyewash and other equipment is working properly
• Keep up-to-date phone numbers
• Dilute substances
• Substitute less harmful substances
• Secure compressed gas chambers (including fire extinguishers)
• Use storage lips to keep from spilling
• Keep chemicals at eye level or lower
• Keep chemicals away from the edge of the table
• Use films and videotapes as substitutes whenever possible

Safe storage of chemicals is required to prevent any unforeseeable accidents that may happen in the storage room. By identifying the types of chemicals that need to be stored, and separating these chemicals, you can insure taht measures are being taken to prevent accidents in the storage room from becoming huge disasters.

One way to identify hazards is to look a the hazard identity discussed earlier. We can also group these hazards another way such as what the Health and Safety website has done:

• Hazard Classes:

1.- Compressed Gases

2.- Severe Poison

3.- Moderate Poison

4.- Water Reactive

5.- Oxidizer

6.- Flammable

7.- Corrosive

8.- Radioactive

9.- Biohazard

Now we can group the hazard classes into compatible categories for storage. We can call these storage groups. Each of these storage groups will be designated with a letter. This letter will then be used in a chart to show compatible storage shelving:

• Storage Groups:

A.- Compatible Organic Bases, Flammables, and Poisons

B.- Pyrophoric and Water Reactive Materials

C.- Compatible Inorganic Bases, Oxidizers, and Poisons

D.- Compatible Organic Acids, Flammables, and Poisons

E.- Compatible Oxidizers, Organic Peroxides and Acids

F.- Inorganic Acids not including Oxidizing or Organic Acids

G.- Non Reactive Materials (Includes Solids, Liquids and Inert Gases)

H.- Flammable Gases (Non-corrosive)

I.- Gases Compatible with Acids and Oxidizers

J.- Poison Gases (Regulated by TGO, may be Flammable but not corrosive)

K.- Explosive or other unstable materials

L.- Solvents, Flammables, and Combustibles

M.- Oxidizing Gases (Non-corrosive)

N.- Needs secondary containment from all groups.

Arranging the groups on the shelves tells us what chemicals can and cannot be near each other:

• Storage Groups that can be stored on the same shelf or within the same cabinet if each group is segregated by secondary containment:

An annual inventory must be taken to insure that safe storage is taking place in the lab. The inventory must take into account the date of storage, the location of each material and the amount of chemicals that are stored there. During inventory, make sure that chemicals are stored properly. Use a database to record chemical storage inventories (Laboratory Safety).

Safe storage practices:

• No hazardous material can be stored immediately over a sink.
• Chemical containers may not be left open.
• Chemicals that are unstable due to age, such as ethyl ether and tetrahydrafuran, must be dated and labeled upon receipt and should be used or disposed before the recommended shelf life expires.

• Store in a properly ventilated area.
• Store liquid chemicals at eye level or lower.
• Store only cleaning materials under the sink.
• Do not store heavy materials on the floor.
• Use a lip on the shelf to catch all the potential spills.
• Use wood shelves if possible.
• Have a smoke detector in the storage area.
• Purchase and store small amounts of chemicals.
• Don’t overcrowd shelves.
• Store overly toxic materials in an explosion-proof cabinet.
• Store dangerous chemicals under lock and key to control student access.
• Keep containers sealed.
• Regularly vent materials that can build up pressure.
• Know alternate names of chemicals to prevent misuse or incorrect storage of chemicals.
• Never store or use phenol in the school.
• Never store or use a chemical without a label.

"People who generate waste have a moral and legal obligation to see that the waste is handled safely" (Fawcett, 52).

Fawcett reminds us that we must not neglect safe practices of disposal when we are dealing with waste that is produced in the laboratory.

There are various methods of disposing of chemicals that can be used in the lab. However, by limiting the amount of chemicals to start with, the disposal of unused chemicals can be minimized a great deal.

One first point about disposing of chemicals is to never pour chemicals back into their original storage containers. This produces a higher chance of the chemical being contaminated with an unknown chemical found in the lab that may introduce a storage hazard that could not be predicted.

Some ways that labs dispose of chemicals are:

• landfilling
• solar evaporation
• acid neutralize
• hydrolysis (in water)
• incineration
• recycling (Fawcett, 162)

Some of these ways may not be acceptable in all situations. Evaporation may be good for some chemicals that do not produce heavy toxins in the air. Recycling may only happen if the chemicals are not put back into their original bottles. Incineration may be dangerous with flammable materials (Fawcett, 164).

Most chemical waste ends up in a landfill. Non toxic substances may be accepted in a sanitary local landfill. More hazardous waste needs to go to a secure landfill which is monitored (Fawcett, 23).

In the classroom, the teacher must deal with disposal of other things besides chemicals. One of the major problems in labs is broken glass. Glass breakage should be disposed of in a separate container than non-glass substances.

Knowing the pyrophoric chemicals in the lab tells us which chemicals should not be disposed of with air, and reminds us to keep those chemicals shut up away from the air. Keeping the reactive hazard chemicals out of the sink together is also another good way to dispose of chemicals. Disposal of water-sensitive chemicals in a separate container instead of using the sink for disposal is also a safe idea.

Specific containers designated for each chemical should be used for disposal of that chemical if it is determined that the chemical cannot be disposed of using the sink. Appropriate containers (in some cases, metal coffee cans work, in other cases, glass disposal also works) is essential to ensure that the chemical does not leak upon transport to a landfill or chemical company that may deal with disposal.

When in doubt, look at the MSDS of the chemical that needs to be disposed. The MSDS will give safety measures on disposal of the chemical.

When a chemical is not labeled properly, the teacher must also dispose of this chemical to insure that the chemical will not be reactive with other materials in the lab. The best method of disposal for this chemical would be to keep it in the appropriate container and dispose of it in a secure landfill, unless there is an alternate policy for your school.

Fawcett, H. (1984). Hazardous and Toxic Materials: Safe Handling and Disposal. John Whiley & Sons: New York

"Health and Safety: Lab activation - Chemical Hazard Management" Retrieved May 8, 2001 from the World Wide Web: http://somsafety.stanford.edu/protocols/activation/chem_hazards_mgmt_contents.html

"Laboratory Safety" Retrieved March 12, 2001 from the World Wide Web: http://web.uvic.ca/ohs/labsafety.html

"Laboratory Safety Course" Retrieved March 13, 2001 from the World Wide Web: http://learn.caim.yale.edu/hhmi/public/

Manitoba Education, Training and Youth. "Science Safety – WHMIS" Chapters 2-8. Retrieved April 12, 2001 from the World Wide Web: http://www.edu.gov.mb.ca/metks4/docs/support/scisafe/

Marsden, N. (1997, April). "Workplace Health and Safety: Hazardous Substances in the Science Laboratory." Austrailian Science Teachers Journal, 3, 45 – 48.

NEA Research Division. (1963). Who is Liable for Pupil Injuries? National Commision on Safety Education: Washington DC

"Safety in the Science Classroom" (1997, April) The Science Teacher, 4, 42-43.

"Safety Services – Safety Bulletin: General Laboratory Safety" (1995, May). Retrieved February 13, 2001 from the World Wide Web: http://www.acs.ucalgary.ca/~ucsafety/bulletins/genlab1.htm

Young, J. (1991). Improving Safety in the Chemical Laboratory: A practical Guide. John Wiley & Sons: New York