A Few Safety Rules

Think through each step before beginning an experiment Identify possible hazards and take appropriate measures

to contain or minimize hazards (read labels) If you don’t know what is going to happen and think

there may be a potential for dangerStop!Get help before proceeding or modify procedure to minimize

risk. When using hazardous chemicals use secondary

containment and appropriate personal protection

Unattended Experiment Guidelines

Prepare for power failure, _______ failure, or a leak__________ containment of hazardous chemicalsPrepare for flooded and ____ conditionsDo not let equipment such as power stirrers, hot plates,

heating mantles, and water condensers run overnight without ________ provisions and the instructor's consent

Everything well secured Check unattended reactions periodically Post contact information Accurate instructions and _______ for emergency

personnel

softwareSecondary

dry

fail‑safe

labels

Routes of Chemical Exposure

skin protective clothing gloves

ingestion don’t pipette by mouth! no food in the lab wash before leaving the lab

inhalation dust and vapors (use fume hood when either are present)

eyes eye protection against splashing and vapors

Material Safety Data Sheets:an information source

Emergency information chemical product and company identification compositionhazards identification

Appropriate response to hazardous situations first aid measures fire fighting measures accidental release measures

Material Safety Data Sheets:an information source

Prevention of hazardous situations handling and storage exposure controls and personal protection physical and chemical properties stability and reactivity

Miscellaneous toxicological information ecological information disposal considerations transportation information regulatory information

Material Safety Data Sheets:an example - Hydrochloric Acid

You’ve been asked to mix up a solution of 1N HCl from concentrated hydrochloric acid. You would like to know of any hazards associated with this procedure.

You remember the safety rule and you think through the steps of preparing the solution. You realize that you’ve never opened a container of concentrated HCl before. So you STOP! and get some help.

Hydrochloric Acid:Potential Health Effects

DANGER! CORROSIVE. CAUSES EYE AND SKIN BURNS. CAUSES DIGESTIVE AND RESPIRATORY TRACT BURNS.

Eye:May cause irreversible eye injury. Vapor or mist may

cause irritation and severe burns. Contact with liquid is corrosive to the eyes and causes severe burns.

Skin:May be absorbed through the skin in harmful amounts.

Contact with liquid is corrosive and causes severe burns and ulceration.

Hydrochloric Acid:Potential Health Effects

Ingestion: May cause circulatory system failure. Causes severe digestive tract

burns with abdominal pain, vomiting, and possible death. May cause corrosion and permanent tissue destruction of the esophagus and digestive tract.

Inhalation: Causes severe irritation of upper respiratory tract with coughing,

burns, breathing difficulty, and possible coma. May cause pulmonary edema and severe respiratory disturbances.

Chronic: Prolonged or repeated skin contact may cause dermatitis. Repeated

exposure may cause erosion of teeth. May cause conjunctivitis and photosensitization.

Hydrochloric Acid

Physical State: LiquidAppearance: Clear, colorless to faintly yellow.Odor: Strong, pungent.pH: 1.1 (0.1N sol).Vapor Pressure: 160 mm HgVapor Density: 1.257 (Air=1)Evaporation Rate: 2.0 (Butyl acetate=1)Viscosity: Not available.Boiling Point: 230_FFreezing/Melting Point: -101_FDecomposition Temperature:3239.6_FSolubility: 823g/L water at 32F.Specific Gravity/Density: 1.19 (Water=1)Molecular Formula: HClMolecular Weight: 36.46

danger!

Hydrochloric Acid:My Solution to the solution

Vapor pressure is significant and vapor is very corrosive

Liquid is very corrosiveSolution preparation should be done in a

fume hood with gloves, protective clothing, and eye protection

MSDS: Hazards Identification

NaClWarning! Causes eye irritation.

HClPoison! Danger! Corrosive. Liquid and mist cause severe burns to

all body tissue. May be fatal if swallowed or inhaled. Inhalation may cause lung damage.

H2SO4

Poison! Danger! Corrosive. Liquid and mist cause severe burns to all body tissue. May be fatal if swallowed or contacted with skin. Harmful if inhaled. Affects teeth. Water reactive. Cancer hazard. Strong inorganic acid mists containing sulfuric acid can cause cancer.

MSDS: Summary

A good source of information on safe handling

May provide useful information on physical-chemical properties

Provide first aid, fire fighting, and accidental release measures

Can be used to obtain concentrations of ingredients in proprietary solutions