Loodchromaat

Loodchromaat, or lead chromate, is an inorganic chemical compound with the formula PbCrO4. It is best known as a bright yellow pigment, historically called chrome yellow, and has been used in paints, inks, and plastics since the 19th century. The solid is sparingly soluble in water and forms a deep yellow powder or crystalline material. In pigment form it provides high opacity and a vivid hue due to its refractive properties.

Production typically involves the reaction of a lead salt with a chromate source under controlled conditions, producing lead chromate as the pigment. In practice, it has been used both as a pure lead chromate pigment and as a component in basic lead chromate pigments (a mixture that can improve stability and hue).

Applications and limitations: Chrome yellow pigments have been widely employed in art and industry for their bright color and coverage. Over time, concerns about toxicity and environmental impact have led to decreased use in favor of safer inorganic pigments and organic yellow pigments. In some formulations, basic lead chromate pigments are used to balance color properties and durability, though they retain lead content.

Safety and environmental concerns: Loodchromaat is toxic due to the presence of lead and hexavalent chromium compounds. Handling of pigment powders requires appropriate safety measures to prevent inhalation or ingestion, and products containing the pigment are subject to hazardous waste regulations for disposal. Lead and chromium(VI) compounds pose health risks, including potential carcinogenic effects for Cr(VI).

See also: Chrome yellow, Basic lead chromate.