Handling and Storage of Hazardous Chemicals direct.com/assets/ite ms/c126.jpg

Characteristics of “Hazardous” Chemicals Cause harmful biological effects Are flammable, explosive or highly reactive Generate harmful vapors or dust Some chemicals assumed to be hazardous because of structural similarity to known hazardous chemicals x?i=Z-PL5&w=200 %20Flammable%20Hazard%20Signs.jpg online.co.uk/minisumo/images/Du st_Hazard.jpg

NFPA Hazard Diamond System

Fire hazards Relates to flash point –0: will not burn –4: below 73 degrees F uploads/image001.gif

Health hazards 0: Normal risk 4: Deadly about/uploads/image001.gif

Reactivity hazards 0: Stable 4: May detonate uploads/image001.gif

Special hazards dabout/uploads/image001.g if Oxidizer Corrosive Acid Alkali Radioactive Use NO water

Flammable Chemicals Flammable = inflammable: relatively easy to ignite and burn

Classes of Flammables Most common = organic solvents –Often volatile Classified by their flash point –Lower flash point = more flammable. Chemicals with flashpoints rated as 3 or 4 should be treated as fire hazards

Working with Flammables Keep away from heat and flame Know how to put a fire out should one occur Keep containers tightly closed when not in use and store away from non-compatible or reactive materials Work in a well-ventilated area Avoid static electricity If a spill occurs, clean off your skin FIRST!!! Large quantities of flammables must be stored in an explosion-proof cabinet

Pyrophoric Chemicals Ignite on contact with air!! materials/images/class42_pyrophoric.gif

Reactive Chemicals Undergo violent chemical reactions –exothermic or gas – generating reactions –unstable chemicals –form peroxides or other oxidizing reagents –incompatible chemical mixtures May cause explosion –Never combine reactive chemicals in a sealed container –Do not use glass for potentially explosive chemical reactions.

Corrosive Chemicals Destroy tissue and equipment on contact –Most common are acids and bases –Will burn skin or eyes –Inhalation hazard Guidelines: –Work in a fume hood –Add acid to water, not reverse –Perform acid-base reactions slowly to minimize gas and heat generation –Wear correct protective gear –Store acids and bases separately –Avoid HF

Toxic Chemicals Can act as a poison, creating biological harm to an organism Acute toxic agents cause damage in a short period of time and can be harmful in a single exposure Chronic toxic agents have cumulative effects or can accumulate in the body with several smaller doses.

Toxic Chemical Handling Know acute and chronic effects of a chemical Be sure you wear the correct gloves Know that odors are not a good guide for exposure level Minimize exposure Be alert to symptoms of sensitization or toxicity Be especially careful with mutagens, carcinogens, and teratogens

Mutagens Compounds that affect the genetic material of a cell –Cumulative and chronic –Assume to be carcinogens

Carcinogens Cancer-causing agents carcin_store_author_person1-lg.gif

Teratogens Embryotoxins that cause fetal malformations

Storage of hazardous chemicals 1. Date chemicals 2. Labels contents and hazards clearly 3. Do not store flammables in standard fridge 4. Sort and store chemicals by hazard: acids bases organic oxidizers inorganic oxidizers flammable liquids flammable solids acute poisons water-reactive

Storing hazardous chemicals 5. Maintain inventory 6. Inspect for leakage or deterioration 7. Keep spill kits on hand

Take-home message ALWAYS CHECK THE SAFETY DATA SHEET AND ALWAYS USE CAUTION WHEN WORKING WITH UNKNOWN CHEMICALS!!!!!