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 danger Stop! 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 chemicals Prepare for flooded and ____ conditions Do 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 software Secondary 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 mention chronic vs. acute exposure

Material Safety Data Sheets: an information source Emergency information chemical product and company identification composition hazards 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 danger! Physical State: Liquid Appearance: Clear, colorless to faintly yellow. Odor: Strong, pungent. pH: 1.1 (0.1N sol). Vapor Pressure: 160 mm Hg Vapor Density: 1.257 (Air=1) Evaporation Rate: 2.0 (Butyl acetate=1) Viscosity: Not available. Boiling Point: 230_F Freezing/Melting Point: -101_F Decomposition Temperature: 3239.6_F Solubility: 823g/L water at 32F. Specific Gravity/Density: 1.19 (Water=1) Molecular Formula: HCl Molecular Weight: 36.46 danger!

Hydrochloric Acid: My Solution to the solution Vapor pressure is significant and vapor is very corrosive Liquid is very corrosive Solution preparation should be done in a fume hood with gloves, protective clothing, and eye protection

MSDS: Hazards Identification NaCl Warning! Causes eye irritation. HCl Poison! 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. Note absence of definitions for good and adequate ventilation!

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