Evaluating the evidence on genotoxicity and reproductive toxicity of carbon black: a critical review

Abstract

Carbon black is produced industrially by the partial combustion or thermal decomposition of gaseous or liquid hydrocarbons under controlled conditions. It is considered a poorly soluble, low toxicity (PSLT) particle. Recently, results from a number of published studies have suggested that carbon black may be directly genotoxic, and that it may also cause reproductive toxicity. Here, we review the evidence from these studies to determine whether carbon black is likely to act as a primary genotoxicant or reproductive toxicant in humans. For the genotoxicity endpoint, the available evidence clearly shows that carbon black does not directly interact with DNA. However, the study results are consistent with the mechanism that, at high enough concentrations, carbon black causes inflammation and oxidative stress in the lung leading to mutations, which is a secondary genotoxic mechanism. For the reproductive toxicity endpoint for carbon black, to date, there are various lung instillation studies and one short-term inhalation study that evaluated a selected number of reproduction endpoints (e.g. gestational and litter parameters) as well as other general endpoints (e.g. gene expression, neurofunction, DNA damage); usually at one time point or using a single dose. It is possible that some of the adverse effects observed in these studies may be the result of non-specific inflammatory effects caused by high exposure doses. An oral gavage study reported no adverse reproductive or developmental effects at the highest dose tested. The overall weight of evidence indicates that carbon black should not be considered a direct genotoxicant or reproductive toxicant.

Applications of Nanocellulose/Nanocarbon Composites: Focus on Biotechnology and Medicine

“…The mechanism of cell damage by nanodiamonds is by generating ROS, and by excessive delivery of sodium ions adsorbed on the nanodiamond surface [168]. Last but not least, carbon nanoparticles can be immunogenic, i.e., they can activate inflammatory reactions, which can be, as has been demonstrated on carbon black, the main pathogenic mechanism of respiratory, cardiovascular and other serious diseases [166,167].…”

“…Although it is considered to have low toxicity, the International Agency for Research on Cancer has classified it as possibly carcinogenic to humans. In addition, as a component of environmental pollution, carbon black can cause oxidative damage and an inflammatory reaction, which further mediate genotoxicity, reproductive toxicity, neurotoxicity and diseases of the respiratory and cardiovascular systems [166,167]. Nevertheless, carbon black is currently used as a filler in tires and in other rubber products, and as a pigment in inks, paints and plastics.…”

Nanotoxicology: The Need for a Human Touch?

“…While they are generally not considered as high‐toxicity materials, rodent studies have clearly shown that nanosized carbon particles are far from completely inactive, being able to instigate both oxidative stress and inflammation. [ 94–97 ] However, such effects are often seen at very high doses associated with lung overload with considerable debate as to whether or not such effects are species specific and therefore of relevance to humans. [ 96 ]…”

The Toxicity of Secondary Lithium-Sulfur Batteries Components

“…Two pieces of information related to the toxicity of Super P carbon were found in literature. Chaudhuri et al [388] considered a carbon black (Super P) as a poorly soluble, weak toxicity (PSLT) particle. However, carbon black may be directly genotoxic, and is also able to induce reproductive toxicity.…”