Is carbon black a nanoparticle?
While primary particle (near spherical building blocks of carbon black) diameters are generally in the 10-300 nanometer range, carbon black products as placed into commerce (the final product) are agglomerates, which are much larger in size (100 - 1000 nanometers in diameter). These agglomerates do not break down into smaller components (e.g., aggregates) because of the effect of van der Waals forces unless adequate force is applied (i.e., shear force). Thus, as placed on the market, carbon black products are not nanoparticles.
Factsheet: Particle properties of CB - PDF
Does carbon black migrate from plastic packaging materials into foodstuffs?
Per scientific investigation, carbon black does not migrate from plastic packaging. Carbon black was investigated to assess the possibility, and if applicable the quantity of nanoparticles migration from plastic materials used in the food packaging industry. Based on this investigation it can be concluded that nanoparticles of carbon black do not migrate into food once it is incorporated into a plastics food contact material.
Investigation: Particle migration– PDF
How is carbon black measured in the work environment?
Carbon black is commonly measured in work atmospheres by general gravimetric methods that collect air samples in the breathing zone of workers over a representative portion of the work shift. In work atmospheres that may contain a dust mixture that includes carbon black, specific methods to measure the elemental carbon composition of the breathing zone sample have been developed by OSHA and NIOSH. An industrial hygienist should be consulted to recommend the sampling and analytical method that is most appropriate.
What is the difference between carbon black and soot?
“Carbon Black and Soot: Two Different Substances”, written by Ann Watson and Peter Valberg, and published in the American Industrial Hygiene Association Journal (Volume 62, pages 218-228) in the March/April 2001 edition, summarizes the differences as follows:
Carbon blacks are manufactured under controlled conditions for commercial use primarily in the rubber, painting, and printing industries. In contrast, soots are unwanted by-products from the combustion of carbon-based materials for the generation of energy or heat, or for the disposal of waste. Greater than 97% of carbon black consists of elemental carbon arranged as aciniform particulate, while depending upon the type of soot, the relative amount and type of carbon and the particulate characteristics in soot can vary considerably (< 60% of the total soot particulate mass is carbon).
Other elements and chemical compounds are associated with the particulate carbon in both substances, though soot has much greater percentages of ash and solvent extractable organic compounds. Additionally, the types of organic compounds found in carbon black are not extractable in biological fluids and are not as biologically potent as those present in soot.
Are Polycyclic Aromatic Hydrocarbons (PAHs) found on carbon black bioavailable?
No. Based on recent in-vitro studies, PAHs contained in carbon black are not bioavailable.