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While working in the science laboratory, you will have certain important _____________ that do not apply to other classrooms. You will be working with materials and apparatus which, if handled carelessly or improperly, have the potential to cause ______ or discomfort to someone else as well as yourself.
responsibilities
injury
It’s the LAW!
Occupational Safety & Health Administration
Basic Safety Rules
Use common sense.
No horseplay.
No unauthorized experiments.
Handle chemicals/glassware with respect.
Others:
#1 Rule:
Safety Features of the Lab
safety showerfire blanketfire extinguishereye washfume hoodcircuit breaker switch
Basic Safety Rules
Use common sense.
No horseplay.
No unauthorized experiments.
Handle chemicals/glassware with respect.
Others:
#1 Rule:
Safety Features of the Lab
• safety shower• fire blanket• fire extinguisher• eye wash• fume hood• circuit breaker
switch
Material Safety Data Sheet (MSDS)
gives informationabout a chemical
-- lists “Dos” and “Don’ts;”
emergency procedures
--
Chemical Exposure
a one-time exposure causes damage
acute exposure chronic exposure
damage occurs after repeated exposure
reaction to drugs
or medication
e.g., e.g., smoking,
asbestos
LD50
There are various ways an LD50 can be expressed. For example, acetone has the following LD50s:
ORL-RAT LD50: 5,800 mg/kgIHL-RAT LD50: 50,100 mg/m3-hSKN-RBT LD50: 20 g/kg
the lethal dosage for 50% of the animals on which the chemical is tested
Example
Which is more toxic?
Chemical A is more toxic because less of it proves fatal to half of a given population.
Chemical A: LD50 = 3.2 mg/kgChemical B: LD50 = 48 mg/kg
LABORATORY SAFETY
• Chemical Hazard Label
• MSDS
• Safety Quiz
Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem
NFPA CHEMICAL HAZARD LABEL
2 34 0
LeastSerious
4
MostSerious
4
0
Flammable vapor which burns readily
Substance is stable
NFPA CHEMICAL HAZARD LABEL
Avoid water.
May detonate
with heat or ignition.
Severe health risk.
Burns readily.Diborane
434
W
HealthHealth (blue)
Chem. nameChem. name
4 – deadly
3 – extreme danger
2 – hazardous
1 – slightly
hazardous
0 – normal material
Fire HazardFire Hazard (red)Flash Point Temp.
4 – below 73oF Temp.
3 – 73 to 100oF – v. flam.
2 – 101 to 200oF – flam.
1 – over 200oF - slightly
combustible
0 – will not burn
ReactivityReactivity (yellow)4 – may detonate
3 – shock or heat may
detonate
2 – violent chem. reaction
1 – unstable if heated
0 – stable
Specific HazardSpecific HazardOXY – oxidizer
ACID – acid
ALK – alkali
COR – corrosive
W – use no water
RAD – radiation hazard
NFPA LabelNFPA Label
MSDS
• Material Safety Data Sheet
• On file for all purchased chemicals.
• Includes all information shown on a chemical label and more.
• Different formats are used by different chemical companies.
Health Hazard
4 Very short exposure could cause death or serious residual injury even though prompt medical attention was given.
3 Short exposure could cause serious temporary or residual injury even though prompt medical attention was given.
2Intense or continued exposure could cause temporary incapacitation or possible residual injury unless prompt medical attention is given.
1 Exposure could cause irritation but only minor residual injury even if no treatment is given.
0 Exposure under fire conditions would offer no hazard beyond that of ordinary combustible materials.
FLAMMABILITY
4Will rapidly or completely vaporize at normal pressure and temperature, or is readily dispersed in air and will burn readily.
3 Liquids and solids that can be ignited under almost all ambient conditions.
2 Must be moderately heated or exposed to relatively high temperature before ignition can occur.
1 Must be preheated before ignition can occur.
0 Materials that will not burn.
INSTABILITY1
4 Readily capable of detonation or of explosive decomposition or reaction at normal temperatures and pressures.
3Capable of detonation or explosive reaction, but requires a strong initiating source or must be heated under confinement before initiation, or reacts explosively with water.
2Normally unstable and readily undergo violent decomposition but do not detonate. Also: may react violently with water or may form potentially explosive mixtures with water.
1Normally stable, but can become unstable at elevated temperatures and pressures or may react with water with some release of energy, but not violently.
0 Normally stable, even under fire exposure conditions, and are not reactive with water.
1 Prior to 1996, this section was titled "Reactivity". The name was changed because many people did not understand the distinction between a "reactive hazard" and the "chemical reactivity" of the material. The numeric ratings and their meanings remain unchanged.
OX This denotes an oxidizer, a chemical which can greatly increase the rate of combustion/fire.
Unusual reactivity with water. This indicates a potential hazard using water to fight a fire involving this material.
This section is used to denote special hazards. There are only two NFPA 704 approved symbols
ACID This indicates that the material is an acid, a corrosive material that has a pH lower than 7.0
ALK This denotes an alkaline material, also called a base. These caustic materials have a pH greater than 7.0
This denotes a material that is corrosive (it could be either an acid or a base).
The skull and crossbones is used to denote a poison or highly toxic material. See also: CHIP Danger symbols.
The international symbol for radioactivity is used to denote radioactive hazards; radioactive materials are extremely hazardous when inhaled.
Indicates an explosive material. This symbol is somewhat redundant because explosives are easily recognized by their Instability Rating.
Aleksza NHHS H-Chemistry 2012-13Safety Quick QuizName:_____________________________________________Score:________/_10__
1. List two safety items in our classroom: (2 points)
A. B.
2. What does MSDS stand for? (2 points)
3. The blue section of the NFPA label represents which type of hazard? (2 points)
4. Provide an example of an acute exposure to a chemical. (2 points)
5. Lab safety and cleanliness is your responsibility too! (2 points)
(A) True (B) False
Aleksza NHHS C- Chemistry 2012-13Safety Quick QuizName:_____________________________________________Score:________/_8__
_____1. Whis is not a safety item in our classroom: (2 points)
A. Hood B. Goggles C. Gas Mask D. Fire Extinguisher
_____2. What does MSDS stand for? (2 points)
A. Material Safety Data SheetsB. Material Support Demostration SuppliesC. Mother Son & Daughter SocietyD. Material Safety Disposal Steps
_____3. The blue section of the NFPA label represents which type of hazard? (2 points)
A. Flamability B. Health C. Reactivity D. Other
_____4. Lab safety and cleanliness is your responsibility too! (2 points)
(A) True (B) False