Кадмий пигменттері: қасиеттері, қолданылуы және қауіптері

Class of pigments that have cadmium as one of the chemical components

Cadmium pigments are a class of pigments that contain cadmium. Most of the cadmium produced worldwide has been for use in rechargeable nickel–cadmium batteries, which have been replaced by other rechargeable nickel chemistry cell varieties such as NiMH cells, but about half of the remaining consumption of cadmium, which is approximately annually, is used to produce colored cadmium pigments. The principal pigments are a family of yellow, orange and red cadmium sulfides and sulfoselenides, as well as compounds with other metals. Cadmium is toxic to humans and other animals in very small amounts, especially when it is inhaled, which often happens when working with powdered pigment or breathing the dust from chalk pastels. As a result, it is not appropriate for children to use any art supplies that contain cadmium pigments. However, because the pigments have some desirable qualities, such as resistance to fading, some adult artists continue to use them.

Cadmium compounds are utilized in coloring borosilicate glass used by artists in lampworking. The palette is often referred to as "cadmium colors" or "cadmium based colors" and is marked by uniquely bright and saturated tones not found in other colored glass. Cadmium pigments used in borosilicate have a relatively short history, with the first commercial formulations hitting the market in 2000 under the name Crayon Colors by Henry Grimmett of Glass Alchemy. Cadmium compound containing glass exhibits a characteristically low heat tolerance when melted, and therefore must be treated with caution when lampworking to avoid boiling off of the cadmium sulfide. CdS has a boiling point of , putting its maximum temperature tolerance as a pigment not far above the working temperature range for borosilicate, which has a softening point of approximately .

Cadmium sulfide is not very toxic ( above 5,000 mg/kg). Cadmium is introduced into the body most commonly through smoking and the diet. Poisoning by pigments is uncommon but of continuing concern. Acute exposure to cadmium vapors can arise from welding near cadmium pigments. In December 2013, the Swedish Chemicals Agency (KEMI) proposed a case to the European Chemicals Agency (ECHA) in favor of restricting or banning cadmium use in artists’ paints, as cadmium in pigments used in other types of paints was already restricted and regulated via TARIC codes and REACH Annex XVII. This proposal stated that cadmium in the body leads to increased risk of bone fractures and breast cancer as well as an array of environmental impacts, and that paint washed down the drain is absorbed by crops that are then consumed, increasing the average dietary cadmium intake. This can cause an array of health effects, including kidney and liver damage, skeletal damage, several types of cancers and death. KEMI's proposal was ultimately declined. In a June 2015 article of Just Paint, published by Golden Artist Colors, the company argued against KEMI's proposal, offering that "There are no alternatives that match all of the characteristics of cadmium pigments." This statement was also included in Golden's response to KEMI's request for information on cadmium pigmented artists’ paints while the agency was composing its ban proposal. The article also stated that a ban would be technically feasible for some artists, but not all, and that "cadmium colors are not for use by children, should not be spray applied or sanded, and unless one is properly protected from exposure and in a non household setting, use of dry cadmium pigment should be avoided." Inhalation poses the greatest risk from cadmium pigments, though the chemical is very low risk when sealed within a pigment particle because of its insolubility. The use of chalk pastels containing cadmium colors is among the highest risks for artists, as these pastels create a dust that can be inhaled.