kemikalier

Kemikalier are substances with a defined composition that can be elements, compounds, or mixtures. They are central to chemistry and are used in almost every sector of modern life, from medicines and cleaning products to fuels and construction materials. Some occur naturally, such as water and minerals, while others are synthesized in laboratories or industrial plants.

Chemicals can be categorized as elements (for example hydrogen or oxygen), compounds (such as water H2O or sodium chloride NaCl), or mixtures (like air or crude oil). Their properties—both chemical (reactivity, acidity) and physical (melting point, density)—determine how they behave and how they should be handled. Many chemicals pose health or environmental risks, and hazard information is standardized through systems such as the Globally Harmonized System (GHS) with pictograms, classifications, and precautionary statements. Safety data sheets (SDS) provide details on handling, storage, exposure controls, and first aid.

Storage and handling require appropriate containment, segregation of incompatible substances, adequate ventilation, temperature control, and the use of personal protective equipment. Clear procedures for spill response and emergency contact information are essential to minimize risk.

Regulation and oversight vary by country but share goals of protecting health and the environment while allowing legitimate use of chemicals. Examples include the EU’s REACH regulation and the US Toxic Substances Control Act (TSCA). These frameworks cover production, labeling, handling, and disposal, and promote safer alternatives and safer design.

Environmental and public health considerations include pollution, persistence, and bioaccumulation. Waste management and recycling reduce impact, while green chemistry seeks to design safer, more sustainable chemicals and processes. Not all chemicals are hazardous; safety depends on dose, exposure route, and context.