Carbon Black

Abstract

Carbon black is a powdered form of elemental carbon in the form of near‐spherical colloidal particles and coalesced particle aggregates of colloidal size, obtained by partial combustion or thermal decomposition of hydrocarbons. It is distinguishable from other commercial carbons, such as charcoal, by its fine particulate nature and the shape, structure, and degree of fusion of the particles observed with the electron microscope. The fundamental unit of a carbon black particle is the aggregate. Although carbon black is often equated with soot, it differs markedly from the unwanted, uncontrolled by‐products of combustion found in chimneys and the ambient air. The contrast between carbon blacks, soots, and diesel particulate is discussed in more detail in the following. Carbon black is the earliest known synthetic pigment, having been produced by the Chinese more than 1500 years ago. They made the ink pigment lampblack by burning purified animal or vegetable oils in small lamps with the flames impinging on cool porcelain surfaces on which the carbon black collected. Carbon black has been commercially produced in the United States for more than 100 years. Although it is still used as a pigment in printing inks, paints, and lacquers, its major use over the past 50 years has been as a reinforcing agent in rubber, particularly in tires. It is also used in plastics, to which it imparts weathering resistance, antistatic, and electrically conductive properties.

Evaluation of biological markers for the risk assessment of carbon black in epidemiological studies

“…This review of the Chinese cross-sectional studies identified showed elevated pro-inflammatory cytokines among workers with considerably high exposure to CB. The mean concentration of 14.9 mg/m 3 measured by personal air samples was up to 4-fold greater than the American Conference of Governmental Industrial Hygienists (ACGIH) threshold limit value (TLV) value for CB of 3 mg/m 3 (inhalable fraction) or worldwide CB OELs which generally range from 2-4 (3 mg/m 3 ) as the inhalable fraction ( 1 ).…”

“…CB particulates are usually highly agglomerated, with 10–1,000 particle aggregates per agglomerate having aerodynamic diameters of up to 200–400 nm. Based on the definition of the European Commission in 2011 that 50% of the primary particles (constituent of the aggregate) measured in the number size distribution have a diameter that is less than or greater than 100 nm, commercially available CB grades fall into one of the two categories: nanoforms of CB or non-nanoforms of CB, with the vast majority of CB grades falling into the nanoform category ( 1 ). In occupational inhalation exposure scenarios, CB particles satisfying the nano definition form agglomerates.…”

Bayesian bias adjustments of the lung cancer SMR in a cohort of German carbon black production workers

“…Currently, greater than 95% of worldwide carbon black production is via the oil furnace black process [ 2 ]. Different grades of carbon black are typically produced by using different reactor designs and by varying the reactor temperatures and/or residence times [ 3 ].…”

Carbon black and lung cancer—testing a novel exposure metric by multi‐model inference

“…Currently, greater than 95% of worldwide carbon black production is via the oil furnace black process [Wang et al, 2004]. Different grades of carbon black are typically produced by using different reactor designs and by varying the reactor temperatures and/or residence times [McCunney et al, 2001].…”