Key Concepts: Hazards and Risk

Hazard and Risk: A hazard refers to anything that might cause harm or damage, including chemicals, radiation, or biological agents. Risk, on the other hand, refers to the likelihood that the hazard would cause harm.
Chemical Hazards: Chemical hazards are represented using symbols. These symbols, known as hazard symbols, communicate the risk posed by the substance. For example, a skull and crossbones symbol indicate a toxic substance.
Categorization of Chemical Hazards: Chemical hazards are categorised into explosive, flammable, oxidising, corrosive, toxic, health hazard, environmental hazard, and gas under pressure.
Risk Assessment: A risk assessment is the process of identifying hazards in a practical and assessing the level of risk they pose. Risk assessments must be conducted before any scientific experiment to ensure the safety of those involved.
Control Measures: Once a risk assessment has been conducted, appropriate control measures need to be put in place to minimise the risks. This could include wearing protective equipment or maintaining safe distances from hazardous substances.
Role of Workplace Regulations: The Control of Substances Hazardous to Health (COSHH) regulations require UK employers to control substances that are hazardous to health. This can involve performing risk assessments, maintaining control measures and providing training in managing hazardous substances.
Hazard Statements and Precautionary Statements: Hazard Statements are standard phrases describing hazards posed by the substance, while Precautionary Statements provide advice on how to handle the substance safely.
Reducing Risks in Chemistry Labs: In a chemistry lab, it’s crucial to use safety equipment like goggles and lab coats to reduce risk, to always wash hands after handling chemicals, to never taste any chemicals and to dispose of chemical waste properly.
Disposal of Chemical Waste: Disposing of chemical waste appropriately is also a part of reducing risk. Certain chemicals need to be disposed of in specified ways to prevent harm to people or the environment.
Impact of Concentration on Risk: The concentration of a substance can significantly affect its risk level. A higher concentration of a substance generally poses a higher risk.
Risk Trade-off: At times, society must weigh the benefits against the harms of using certain hazards—this is known as risk trade-off. For instance, certain drugs may have side effects but offer significant benefits to patients.

This key concepts guide is meant to simplify the understanding of hazards and risk from a chemistry perspective. Remember to refer to detailed chemistry texts and practise question papers for comprehensive understanding and application.