Chemical Safety in Laboratories

Chemical Laboratory Safety Orientation

• Chemical laboratory work involves hazardous materials.
• Accident prevention is a shared responsibility among all lab personnel.
• Safe practices are essential, not just preferred.

Fundamentals of Chemical Laboratory Safety

• Every day chemicals used in laboratories can be hazardous.
• Preventing accidents is the responsibility of every lab member.
• Safe practices are crucial in laboratories.

Personal Protection Equipment (PPE)

• Wear appropriate PPE
  • Chemical splash goggles
  • Chemical-resistant apron
  • Shoes that fully cover the whole foot
  • Safety gloves
  • Face mask (not surgical)

Laboratory Protocol

• Do not engage in unauthorized activities, including practical jokes or unsanctioned experiments.
• Avoid unnecessary running or conversations in the laboratory.
• Prohibit using personal audio or video equipment in the laboratory.
• Do not sit on lab work areas or sinks
• Do not work unsupervised.

General Work Procedures

• Exercise caution when handling hot glass and apparatus.

• Hot glassware looks just like cold glassware, so always treat it carefully.

• Avoid pipetting chemicals by mouth. Always use pipetting aids or suction bulbs.

• Report any spills, incidents, or injuries to the teacher immediately.

• Ensure there are no flammable solvents in the vicinity during flame tests.

• Turn off all heating equipment, gas valves, burners, and water faucets when not in use.

• Store lab coats, bags, and other personal items in designated areas; not on lab benches or aisles.

Housekeeping

• Never place materials, particularly chemicals, on the floor, even temporarily.
• Maintain well-organized workspaces and storage areas free of broken glass, surplus chemicals, and unnecessary items.
• Never obstruct access to exits or emergency equipment.
• Verify all equipment for damage prior to its use.

Hygiene Practices

• Avoid touching your face, eyes, mouth, and body with chemicals.
• Foods and drinks are not permitted within the laboratory area.
• Wash your hands carefully after removing gloves and before leaving the laboratory.

Emergency Procedures

• Know the location of all exits and follow the emergency plan.
• Know how to operate fire extinguishers, fire blankets, alarm systems with pull stations, eyewashes, safety showers, and first aid kits.

Chemical Handling Procedures

• Verify the label before using any chemical to ensure it's the correct substance.
• Utilize spatulas to remove solid reagents from containers.
• Hold containers away from your body when transferring liquids or chemicals.
• Measure only the required amount of chemical and do not return any excess to its original container.

Waste Disposal

• Do not discard chemical waste down the laboratory sinks.
• Dispose of chemical wastes in properly labelled containers.
• Properly dispose of broken glassware and sharp objects (e.g., syringe needles) in designated containers.
• Place waste paper products that aren't chemical laden in the appropriate trash receptacles.

Safety Considerations

• Hazards are danger sources (like chemicals, electricity, hot surfaces, etc.).
• Risk is the likelihood of a hazard occurring, considering the length of exposure.
• Consequence is the outcome or impact of exposure to a hazard.

Physical Hazards

• Heat and fire cause thermal burns.
• Cryogens cause frostbite.
• Ultraviolet exposure causes sunburn.
• Explosions (chemical reactions, compressed gases) lead to projectile injuries, impacts/bruises, or injections.
• Noise leads to hearing damage.

Ergonomic Hazards

• Repetitive motions, heavy lifting, workspaces design (computers, instruments), and awkward postures cause discomfort.

Bio Hazards

• Bloodborne pathogens (AIDS, HIV, hepatitis) are found in clinical chemistry labs and labs involving genetic engineering/cloning, animal work, and zoology.
• Zonotic diseases originate from animals.

Radiation Hazards

• Ionizing radiation (alpha, beta, gamma, X-rays, neutrons) and radioactive isotopes (tritium H-3, carbon C-14, sulfur S-35, phosphorus P-32/33, iodine I-135) are dangerous.

Fire and Explosion Hazards

• Flammable solvents, pyrophoric materials, and spontaneous combustion pose fire hazards.

Special Chemical Substances

• Controlled substances (drugs, psychotropics, hallucinogens, heroin).
• Chemical warfare agents (nerve gas, phosgene, riot control agents) are particularly dangerous.

Chemical Exposure

• Chemical exposures occur via physical and health routes (air, water, food, soil, products).
• Toxicities depend on concentration, frequency, duration, and exposure route.
• Physical hazards include chemical burns (acids/caustics), physical burns (flammables/combustibles), explosions (chemical reactions/compressed gases), and asphyxiation (lack of oxygen).
• Health hazards include irritants, allergens/sensitizers, reproductive/developmental toxins, carcinogens, target organ effects, and chemical asphyxiants.

Routes of Exposure

• Inhalation is a significant mode of chemical exposure, especially when working in the breathing zone. Others include absorption, ingestion, and injection.

How to Avoid Accidents in the Lab

• Point test tubes away from yourself and others.
• Look at test tube contents from the side.
• Tie back loose hair to prevent contact with lab materials.
• Never taste substances without a direct instruction; instead, fan your hand by the substance to direct the odor/smell to your nose.

Chemicals on Skin, Clothing, and Eyes

• Flush spills immediately with a safety shower.
• Launder contaminated clothes separately.
• Rinse any eyes exposed immediately with the safety eyewash.
• For chemical burns, wash with cold water for 10 minutes.
• For organic burns, use soap to emulsify the substance, then wash with water

Spill Cleanup

• Immediately and efficiently clean up spills.
• Absorb excess liquid using absorbent materials.
• Wear appropriate PPE.
• Use tongs/forceps to pick up broken glassware.
• Clean from outside to inside the spill area.
• Avoid dry sweeping.

Material Safety Data Terminology

• Poison: Material with toxic effects.
• Toxin: Poisonous substance.
• Acute: Rapid onset of toxic effects.
• Chronic: Toxic effects develop over time.
• Cumulative: Toxins accumulate in the body.
• Carcinogen: Cancer-causing material.
• Mutagen: Material that causes genetic mutations.
• Teratogen: Material that causes birth defects.
• Caustic: Substance that burns or damages tissue.
• Explosive: Substance that can explode.
• Oxidizer: Substance that can cause other materials to catch fire.
• Peroxide former: Substance that forms peroxides when exposed to air/water
• Flash point: Lowest temperature at which a liquid vaporizes and ignites.
• Corrosive: Damages or destroys materials.
• Lacrimator: Produces eye irritation.
• Flammable: Substance that ignites easily.
• Inflammable: Same as flammable
• Combustible: Substance that catches fire.

Chemical Labeling

• Primary container labels include manufacturer, hazards, and identity.
• Secondary container labels display hazards (descriptions, icons, etc.).

Labeling: NFPA and DOT

• Understanding the NFPA 704 and DOT safety symbols is critical for recognizing chemical hazards and risks.

Fire Safety

• Preventing fires is the best approach.
• Correctly use fire extinguishers, following the PASS method (Pull, Aim, Squeeze, Sweep).
• Know when NOT to tackle a fire (e.g., too large, spreading rapidly, blocking escape routes, inadequate PPE).
• Immediately leave the area in such situations; contact relevant authorities.
• If a person's clothes catch fire, have them STOP, DROP, and ROLL.
• Use a blanket or rug to smother flames, if applicable.

Emergency Situations and Actions

• Be ready for building alarms, earthquakes, and medical emergencies.
• If a criminal act occurs, move to safety and contact relevant authorities.
• Handle chemical or radioactive spills/contamination appropriately and contact relevant authorities.
• In all cases of emergency, follow safety protocols: ensure you are safe first, then assist others.

How to Handle Laboratory Accidents

• Dealing with incidents is just as critical as avoiding them.

Chemical Toxicity

• Understand that all substances are potentially harmful; the dosage determines harm.
• Recognize the distinction between acute (rapid onset) and chronic (prolonged) toxicity.