Chlorine production with asbestos usage

Chlorine Production: Asbestos Still Used

You may be shocked to learn that even in the 2020’s, asbestos is still used in the chlor-alkali industry.  This continued use of asbestos by the chlor-alkali industry has rightfully come under heavy scrutiny as the EPA has finally proposed an outright ban on chrysotile asbestos – the type of asbestos fiber used in the manufacture of chlorine.

Historical Significance

For decades, asbestos played a pivotal role in the chlor-alkali sector due to its exceptional properties, including resistance to heat, durability, and chemical resilience. This made it an attractive choice for constructing diaphragm cells and related equipment, essential in the chlor-alkali process. However many benefits – they should have been far outweighed by the hazard to human health posed by asbestos.  

Shifting Safety Paradigms

Since at least the 1970s, when OSHA and the EPA began to regulate asbestos, there has been a heightened awareness of the grave health risks linked to asbestos exposure. Inhalation of asbestos fibers is known to cause diseases like mesothelioma, prompting stringent regulations to safeguard the well-being of workers and the environment.  Nevertheless, the chlor-alkali industry has continued to use asbestos in electrolysis diaphragms used to make chlorine.  The diaphragms to separate chlorine from sodium hydroxide in the sodium chloride electrolysis process. The use of asbestos in these diaphragms – which has continued into 2023 – is  a practice which places workers at risk of developing numerous asbestos disease including mesothelioma and lung cancer.  

Regulatory Constraints

Asbestos usage in chlorine production has come under increasing scrutiny in the United States as the EPA in December 2020 found a health risk to chlor-alkali workers from the continued use of asbestos.  The EPA has proposed a ban on chrysotile asbestos, the type of asbestos used in the chlor-alkali process.  The ban is expected to be finalized in late 2023.  These measures aim to minimize asbestos exposure and mitigate the associated risks to both chlor-alkali workers and the community. 

Seeking Safer Solutions

In response to these regulatory constraints, the industry has actively explored alternative materials for constructing diaphragm cells and related equipment. Materials such as polymer-based membranes and advanced coatings have emerged as promising substitutes for asbestos. These alternatives are designed to maintain the integrity of the chlor-alkali process while eliminating the health risks tied to asbestos. As of the summer of 2023, the few chlor-alkali producers using asbestos have announced that in light of the looming EPA ban, they are also phasing out asbestos diaphragms.

Environmental Implications

In addition to health concerns, there are noteworthy environmental considerations associated with asbestos use in chlorine production. The disposal of asbestos-containing materials poses a significant environmental challenge due to its hazardous nature. The transition to safer alternatives not only prioritizes human health but also contributes to environmental sustainability.

Asbestos’s role in chlorine production has transformed significantly over time. Although it once played a pivotal part in the industry, concerns over health and the environment have led to its gradual phase-out. The implementation of regulatory measures and the exploration of safer alternatives have reshaped the landscape of the chlor-alkali industry. Action by the EPA was crucial in finally bringing to an end the last ongoing use of asbestos in the United States.