Chemistry Laboratory

Chemical Risk Pictograms

Introduction to Laboratory Safety

Laboratory safety is fundamental to prevent accidents and protect the health of students, teachers, and staff. A chemistry and biology laboratory contains materials and equipment that can be dangerous if not handled correctly.

Basic Safety Principles

The fundamental principles governing laboratory safety include:

• Prevention: Anticipate risks before they occur
• Protection: Use appropriate protective equipment
• Preparation: Know emergency procedures
• Prudence: Act with caution and common sense

Types of Laboratory Risks

Laboratories present various types of risks:

• Chemical risks: Poisoning, chemical burns, dangerous reactions
• Physical risks: Cuts, thermal burns, electrical shocks
• Biological risks: Infections, cross-contamination
• Ergonomic risks: Inadequate postures, repetitive movements

General Safety Standards

Personal Clothing and Protection

Proper use of personal protective equipment (PPE) is essential:

• Laboratory coat: Preferably cotton, long sleeves
• Safety goggles: Mandatory at all times
• Gloves: Select appropriate type according to chemical
• Closed footwear: Shoes that completely cover feet
• Hair tied back: Long hair must be tied back

Laboratory Behavior

Behavior rules include:

• No eating, drinking, or smoking in the laboratory
• Wash hands before and after each practice
• Don't work alone in the laboratory
• Keep work area clean and organized
• Report any accident or spill immediately
• Don't perform unauthorized experiments

Chemical Substance Handling

Hazard Classification

Chemical substances are classified according to their hazard:

• Explosives: Can explode from impact, friction, or heat
• Flammables: Ignite easily
• Oxidizers: Favor combustion
• Toxic: Cause harm to the organism
• Corrosives: Destroy living tissue and materials
• Irritants: Cause inflammation in skin and mucous membranes

Labeling and Pictograms

The Globally Harmonized System (GHS) establishes universal pictograms to identify chemical hazards:

• Red diamond with flame: Flammable
• Red diamond with exploding bomb: Explosive
• Red diamond with skull: Acute toxic
• Red diamond with corrosion: Corrosive
• Red diamond with exclamation mark: Irritant

Safe Storage

Storage rules include:

• Separate incompatible substances
• Keep containers tightly closed
• Store in cool and ventilated places
• Use appropriate and safe shelving
• Clearly label all containers

Laboratory Safety Equipment

Emergency Equipment

Every laboratory should have:

• Emergency shower: For complete body washing
• Eyewash: For emergency eye irrigation
• Fire extinguisher: Appropriate for different fire types
• Fire blanket: To smother fires on clothing
• First aid kit: With basic materials
• Spill kit: To contain and clean spills

Ventilation and Fume Hoods

Fume hoods are essential for working with toxic or irritating vapors. Proper use includes:

• Verify it works before using
• Work with sash at appropriate height
• Don't put your head inside the hood
• Keep materials at least 15 cm inside

Emergency Procedures

In Case of Chemical Spill

1. Alert nearby people
2. Evaluate the nature of the spill
3. Use appropriate spill kit
4. Ventilate area if necessary
5. Clean from outside toward center
6. Dispose of contaminated materials correctly

In Case of Fire

1. Activate fire alarm
2. Turn off electrical equipment if safe
3. Use appropriate extinguisher for fire type
4. Evacuate if fire cannot be controlled
5. Never turn your back on fire when exiting

In Case of Chemical Contact

• Skin: Wash with abundant water for 15 minutes
• Eyes: Irrigate with water in eyewash for 15 minutes
• Inhalation: Move to fresh air immediately
• Ingestion: Don't induce vomiting, seek medical attention

Waste Management

Waste Classification

Laboratory waste is classified into:

• Non-hazardous waste: Paper, cardboard, inert materials
• Chemical waste: Solvents, acids, bases, heavy metals
• Biological waste: Cultures, tissues, contaminated material
• Radioactive waste: Material with radioactivity

Segregation and Labeling

Principles for waste management:

• Separate at point of generation
• Use appropriate and labeled containers
• Don't mix incompatible waste
• Minimize waste generation
• Document hazardous waste generation

GHS Safety Pictograms

The Globally Harmonized System (GHS) of classification and labeling of chemical products establishes universal pictograms to communicate chemical substance hazards.

GHS01: Explosive

GHS02: Flammable

GHS05: Corrosive

Practical Safety Examples