Chemical-Safety

Chemical Safety

• Importance of handling and using chemicals safely

Outline

• Key topics to understand and review:

  • Introduction: Case Studies

  • Hazard Communication

  • Material Safety Data Sheet (MSDS)

  • Globally Harmonized System (GHS) of Chemical Labeling

  • Chemical Exposure

  • Personal Protective Equipment (PPE)

  • Chemical Storage

  • Chemical Spill Response

  • Waste Disposal

  • General Safety Rules

Case Study: Petroleum Ether Incident

• Petroleum ether stored improperly in a domestic freezer:

  • Poor sealing led to evaporation exceeding explosive limits (1.0%).

  • Flash point: -50℃.

  • Caused $500,000 damage due to ignition from a spark.

University of Missouri Explosion (2010)

• Ignored warning systems for hydrogen gas:

  • Excess hydrogen accumulation led to explosion upon ignition.

  • Resulted in 4 injuries, one critically.

  • Anaerobic hood defined as oxygen-free chamber for sensitive bacteria work.

Hazard Communication

• Workers informed about chemical hazards:

  • Essential communication through:

    • Labels

    • Material Safety Data Sheet (MSDS)

    • Education and training sessions

Material Safety Data Sheet (MSDS)

• Document detailing chemical properties and hazards:

  • Includes:

    • Physical and chemical properties

    • Health and physical hazards

    • Exposure routes and safe handling precautions

    • Emergency procedures and control measures

Globally Harmonized System (GHS)

• Standardized system for classifying and labeling chemicals:

  • Defines hazards and communicates safety information internationally.

  • Adopted for consistency in label content and format.

GHS Pictograms

• Visual symbols indicating various hazards:

  • Examples include:

    • Carcinogens

    • Flammables

    • Respiratory sensitizers

    • Toxicity hazards

Toxicity and Risk

• Definitions:

  • Toxicity: Chemical’s capacity to cause harm.

  • Risk: Likelihood of harm occurring with use.

  • Safe handling allows even toxic chemicals to be utilized safely.

Chemical Exposure Routes

• Main routes through which exposure can occur:

  • Inhalation: Breathing in fumes or powders.

  • Ingestion: Chemicals entering via mouth.

  • Injection: Through skin via needles.

  • Absorption: Through skin or mucous membranes.

• Classifications based on duration:

  • Acute: Immediate effects (irritation, dizziness, etc.).

  • Chronic: Long-term health issues.

Hierarchy of Risk Controls

• Steps for chemical safety:

  • Eliminate hazards where possible.

  • Substitute safer materials or processes.

  • Implement engineering controls (e.g., fume hoods).

  • Provide training and establish administrative controls.

  • Utilize PPE (gloves, lab coats, eye protection).

Personal Protective Equipment (PPE)

• Wearable gear to limit exposure to hazards:

  • Protects against chemical, radiological, and physical dangers.

High Hazard and Minimum Lab PPE

• High hazard area PPE should include:

  • Flame-resistant lab coats, goggles, gloves

  • Proper training on use and maintenance is essential.

Case Study: Sheri Sangji (2008)

• Incident involving t-butyl lithium:

  • Introduction of air into a syringe caused flash fire.

  • Inadequate PPE led to serious burns and ultimately death.

Case Study: Karen Wetterhahn (1997)

• Exposure to dimethylmercury:

  • Accidental spill through latex gloves led to severe mercury poisoning.

  • Highlighted limits of common PPE.

Chemical Storage

• Safe practices include:

  • Routine inspections and stringent inventory controls.

  • Minimize chemical quantities, ensure proper segregation, and adhere to storage conditions.

Chemical Spill Response

• Safety steps during a spill:

  • Assess severity and respond according to training.

  • Avoid contamination; use proper PPE; consult MSDS for guidance.

Chemical Fire Response

• Initial steps in fire case:

  • Attempt to extinguish if manageable; ventilate; ensure safe evacuation if not.

Hazardous Waste Management

• Guidelines for handling waste:

  • Avoid pouring chemicals down drains; classify waste types appropriately.

  • Utilize flame-resistant containers for storage; arrange for proper disposal.

General Safety Rules

• DOs:

  • Store chemicals in original containers; wear appropriate safety gear.

  • Properly dispose of chemicals; manage glassware care.

• DON’Ts:

  • Avoid unnecessary chemical purchases; don't consume near chemicals.

  • Do not use unlabeled containers; avoid pipetting by mouth.

Conclusion

• Proper chemical safety procedures are essential for a safe working environment in labs. Always follow regulations and maintain vigilance.