Cobalt Institute Standing for Realism in Cobalt Workplace Science and Regulations
Recently, the International Agency for Research on Cancer (IARC) performed an evaluation of inherent toxic properties relating to cancer for groups of cobalt substances, where, based on animal data, they indicated a hazard for cancer exists with certain cobalt substances. To date, cancer from cobalt exposure has only been observed in animal studies, and in direct contrast, excess cancer related to cobalt exposure has not been observed in cobalt workplaces. Despite this, the European Commission, with ECHA and its Risk Assessment Committee, have recently launched scientific work to set an EU-wide binding Occupational Exposure Limit value or OEL.
To evaluate if an inherent hazard observed in animal studies translates to a risk to human health (lung cancer), information on exposure in the workplace, and scientific data relating to the cause of cobalt-related cancer, is required. The Cobalt Institute has a history of research, assessment and reporting of the best science to inform any regulatory initiative around safe production and use of cobalt and its substances. This article sheds some light on the Institute’s main hurdle when defending the existence of safe levels of exposure to cobalt in the workplace: demonstrating the existence of that threshold, and numerically identifying the value that this safe level should have.
Cobalt is essential to life – for humans in the form of Vitamin B12 and for other animals in the most basic form of the cobalt ion. As with any essential element, both too much and too little can result in deficiencies or toxicities. This is considered as a ‘U’ shaped dose response (i.e., relationship between amount and effect) in which the bottom of the U represents a window where no deficiency or toxicity (no adverse effect) would be expected to occur.
As a versatile element, cobalt can be used in different forms and in many different sectors for various and sometimes niche applications. All of these rely on the inherent properties cobalt brings to the products and processes. One of these inherent properties is the reactive nature of cobalt, and while this is invaluable for certain applications, above certain levels and under insufficiently controlled conditions, cobalt’s reactivity may lead to detrimental effects on human health. In particular, long exposures to excessively high amounts of very fine cobalt dusts can cause lung irritation and chronic toxicity.
With investigation of lung cancer as the ultimate outcome, the Cobalt Institute and Cobalt REACH Consortium (CoRC) have performed studies over the last decade to shed more light on the biological mechanisms that, when altered, can contribute and lead to this effect. The CI has published and organized the data into several tiers of information – ranging from the small (i.e., cellular) to the large-scale (whole body); which can be used to group cobalt substances into those that can potentially cause cancer in rodents (and in translation, to humans) and those that potentially have a different ultimate outcome.
During the course of generating this data and evaluating the mechanisms behind cobalt adverse effects, alongside a lack of observed cases of lung cancer in humans, the only coherent and biologically understandable outcome when looking at this substantial database, was the existence of a safe level in the relationship between cobalt exposure in the workplace and lung cancer in humans.
This being said, the use of cobalt in EU workplaces has come under scrutiny, with recent proposals from regulatory bodies in e.g., Germany or the larger EU. While they acknowledge that a non-toxic level of exposure to cobalt theoretically exists, because they cannot identify the value of that level from animal studies, these regulators use another dose-response curve shape when scrutinizing cobalt: the so-called “linear” or “non-threshold” dose-response curve. This curve infers that there is a direct correlation between any and all levels of cobalt exposure, and cancer. The use of a linear dose-response curve however, can only lead to very unrealistic occupational exposure levels being proposed by the regulators. Indeed, among others, it contradicts the existence of an essential amount of cobalt necessary for human health.
Through their research and scientific assessment, the Cobalt Institute and Cobalt REACH Consortium (CoRC) have combined all available animal and human data to predict the exposure values which would characterize the bottom of the ‘U’ dose-response curve for cobalt. This has been supported by external experts and will be the foundation of the Institute’s advocacy towards regulators during the OEL-setting process and other relevant regulations worldwide.
The cobalt industry has always moved proactively to protect workers from the potentially harmful effects of cobalt and is now supporting a workplace level for cobalt exposure that takes into account robust (and realistic) scientific assessment, feasibility of achieving set exposure levels and consideration of cost to industry. A proportionate regulatory approach for cobalt is essential to enable the technology needed for a greener and more circular future, and the advancement of society.