Renhetsgrader

Renhetsgrader, literally meaning purity grade, is a term used to describe the degree of purity or cleanliness of a substance, material, or environment. It expresses how much of the desired component is present relative to impurities or contaminants, and can be conveyed as a grade, percentage, or class.

The concept appears across many fields. In chemistry and pharmacology, purity grades indicate suitability for different applications: reagents or solvents may be labeled technical, analytical, or pharmaceutical grade, each with defined impurity limits. In metallurgy and materials science, metals and compounds are specified by purity levels (for example, high-purity metals reaching 99.9% or more), which influence properties and performance. In environmental science and industrial settings, renhetsgrader also describe cleanliness of air or water, with classifications based on contaminant concentrations and regulatory thresholds. Cleanroom standards, such as those defined by ISO 14644, relate environmental renhetsgrader to particle counts and controlled conditions.

Measurement and notation of renhetsgrader rely on quantitative methods. Purity is often reported in percent, parts per million, or other concentration units, and impurities are identified through analytical techniques such as spectroscopy, chromatography, mass spectrometry, or titration. The term is widely used in product specifications, quality control, and safety assessments to facilitate comparison and compliance across processes and industries.

See also: Purity, Cleanliness, Purity grade, Cleanroom, ISO 14644, Pharmacopoeia.