Chemistry

SAFETY IN THE LABORATORY

SAFETY IN THE LABORATORY

• While no human activity is completely risk free, if you use common sense and a bit of chemical sense, you will encounter few problems.

• Chemical sense is an extension of common sense. Sensible laboratory conduct won't happen by memorizing a list of rules, any more than a perfect score on a written driver's test ensures an excellent driving record.

Rules of Laboratory ConductAvoid Horseplay

– In a laboratory setting, horseplay, even if good-natured, is absolutely unacceptable. • No pushing; no shoving.

• Use equipment only for its intended use

Rules of Laboratory Conduct

Perform laboratory work only when your teacher is present. Unauthorized or unsupervised laboratory experimenting is not allowed.

Rules of Laboratory Conduct

First Aid in the Laboratory • Report ALL accidents, injuries, and spills

to your teacher IMMEDIATELY!!!– You must know: – Safe Laboratory techniques – Where and how to report an accident, injury,

or spill – Location of first aid equipment, fire alarm,

phone.

• First Aid Kit  – These items may be used temporarily for small injuries

(say, a cut finger) – Go to the school nurse immediately afterward. – Do not wait until the end of the day. – Do not come into contact with another person's blood. Let

the injured person apply his/her own bandage.

Rules of Laboratory ConductPrepare for each laboratory

activity by reading the entire lab before entering the lab area. Ask questions about any procedure you are unsure of. Follow all directions implicitly and intelligently. Make notes of any modifications to the procedure given by your teacher.

Rules of Laboratory Conduct

A messy work area is often a safety hazard!

• Clear your bench top of all unnecessary materials such as books and clothing before starting your work.

Rules of Laboratory Conduct

Broken Glass

 – Sweep it up right

away – Don’t track in it all

period.

Broken Glass Container

Broken Glass: DON'T throw broken glass into the waste basket.

DO use a special thick-walled container for broken glass.

Rules of Laboratory Conduct

Wear a laboratory coat or apron and protective glasses or goggles for all laboratory work. Wear shoes (rather than sandals) and tie back loose hair

Rules of Laboratory Conduct• Many states require by law

that students wear approved safety goggles or safety glasses when in the lab. This is an absolute "MUST"!

It's the LAW! Eye protection must be worn at all times you are in the lab.

• Eye protection must cover the eyes, not the chest or forehead.

Severe burn from alkali Minor acid burn

Corneal scarring

Rules of Laboratory Conduct

Never taste laboratory materials. Gum, food, or drinks should not be brought into the laboratory.

A good practice is to assume everything in the lab is toxic.

Rules of Laboratory Conduct

• DO NOT drink from lab equipment.

• NOT EVEN distilled water.

– You do not know what another person might have added to the "distilled water" jug.

Rules of Laboratory Conduct

Know the location and use of all safety equipment in your laboratory. These should include the safety shower, eye wash, first-aid kit, fire extinguisher, and blanket.

• Eyewash • Shower • Fire blanket • Broken glass container • Goggles cabinet • Fume hoods • Fire extinguishers • Spill Clean-up Kits • Fire Alarm

Rules of Laboratory Conduct

• Minor skin burns should be placed under cold, running water.

• In case of a chemical spill on your skin or clothing rinse the affected area with plenty of water. If the eyes are affected water-washing must begin immediately and continue for 10 to 15 minutes or until professional assistance is obtained.

EyewashEyewash Fountain If you get a

chemical in your eye -- wash it out immediately! Use the eyewash fountains (but run some water through before you wash your eye). Retract your eyelid (do not squint -- it restricts water access). Afterward, go to the health center. Take your lab book so that the medical personnel can know with what you were working at the time of the accident.

Safety Shower

Safety Shower If you or a classmate is on fire -- go (or direct him/her) to the entrance doorway to the lab. Find and pull the brass ring. Many gallons of water will be dumped from the shower on the ceiling to extinguish the blaze instantly.

Fire Blanket

Yank the blanket out of the wall holder. Wrap it around the victim to smother the fire.

                                                               

Fire Extinguisher Operation

There are two main types of fire extinguishers,

»carbon dioxide Carbon dioxide extinguishers are good, general purpose

extinguishers.

»dry chemical (powder) Dry-chemical (powder) are used for difficult cases, say

certain types of electrical fires. AVOID using a dry-chemical extinguisher on a fellow human being. The powder may get in the victim’s eye and cause irritation.

• Often, but not always, they carry different colors.

• In this case the carbon dioxide extinguisher is red, and the dry-chemical (powder) extinguisher is yellow.

• Read the tag to know which you will use. The tag also should show the date the extinguisher was last serviced.

USAGE:  

Locate the "KEY" (the round object)

Twist the "KEY" to break the stiff Nylon retaining cord

then pull "KEY" out Do not merely attempt to pull the

key straight out, unless you are very strong.

Raise the nozzle in order to direct the stream of carbon dioxide

The CO2 will cool the fire, and restrict oxygen

The fire, lacking oxygen, should go out.

• Squeeze the handle to begin operation.

Rules of Laboratory Conduct

Operate electrical equipment only in a dry area with dry hands.

Rules of Laboratory Conduct

Hot and cold glass have the same visual appearance. Determine whether an object is hot by bringing the back of your hand close to the object.

Rules of Laboratory Conduct

When discarding used chemicals, carefully follow the instructions provided.

Return equipment, chemicals, aprons, and protective glasses to their designated locations.

Before leaving the laboratory, ensure that gas lines and water faucets are shut off.

Wash all glassware and return any equipment to its proper storage place.

Wash hands before leaving the lab area.

If in doubt, ask!

Rules of Laboratory ConductTESTING of ODORS:

Do NOT smell the flask directly.

   

  If you are instructed to smell something, do so by fanning some of the vapor toward your nose. Do not place your nose near the opening of the container.

Rules of Laboratory Conduct

Make sure that reaction tubes, e.g. test tubes, are not directed toward yourself or other persons.

The chemicals may splatter out the tube.

A better technique:

Rules of Laboratory Conduct

• You may be asked to transfer some laboratory chemicals from a common bottle or jar to your own test tube or beaker. Do not return any excess material to its original container unless authorized by your teacher.

Rules of Laboratory Conduct

• Make sure the rubber hoses are firmly attached.

• Both at the gas outlet and at the burner.

• Otherwise, the flame may "strike-back".

• Ask your teacher what this term means.

Turn up the gas flow until you hear a gentle flow of gas.

 

– Light the burner by bringing the match UP from the base toward the burner nozzle.

•   – The match should be

quenched with water, NOT thrown into the waste directly.

• Fires may occur.

Terms You Need to Know:• Highly Toxic: Agents or substances that

when inhaled, absorbed or ingested in small amounts can cause death, disablement, or severe illness.

• LD50: the amount of a substance which will cause death to 50% of a population.

• Explosive: an unstable substance capable of rapid and violent energy release.

• Volatile: Easily vaporized from the liquid, or solid state.

Terms You Need to Know

• Corrosive: a substance that causes destruction of tissue by chemical action on contact.

• Irritant: a substance that on immediate, prolonged, or repeated contact with normal tissue will induce a local inflammatory reaction.

• Flammable: Burns easily.

Hazard Diagram

• The hazard diagram is widely used to indicate the health, fire, and reactivity of chemicals.

• This diagram is not only found on the label of bottles of chemicals, but on boxes, tractor trailers, railroad cars, and anywhere that chemicals might be stored.

• It is important to be familiar with this diagram and what the number in each section indicates in regards to the hazard presented by the chemical to which it is referring.