Antimony trioxide industry pushes back on debate to reduce specialty chemical in fire retardants

By Martim Facada
Published: Thursday, 15 November 2018

There can be no trade-off between chemical and fire risk, event delegates said of the debate on substituting antimony trioxide in flame retardants due to its intrinsic toxicity.

Attendees of International Antimony Association Day in Brussels on 13-14 November said that despite the minimal scientific support based only on studies made on animals, the debate to replace antimony trioxide in flame retardants could induce policy-making that trades off chemical and fire risk. 

"There is no evidence from the antimony field that antimony provokes cancer. Over the past 40 years Campine employees never had cancer issues as a result of handling or interacting with antimony trioxide," Hans Vercammen, the business unit manager for the specialty chemicals business unit at Campine, told Fastmarkets. 

Concerns of the effect of this specialty chemical to human health, related to its potential carcinogenicity, has continued to feed the debate for removing it in flame retardants. Professionals from the industry say there should be no trade-off between toxicity and flame retardancy, emphasizing that safety in both is needed.

The reduction of antimony trioxide in flame retardants increases the risk of flammability and greater exposure to fires in households or workplaces, other antimony industry professionals told Fastmarkets at the event.   

"Antimony trioxide makes the use of bromine more resource and cost-efficient, increasing the performance of the flame retardant polymer containing these, while reducing the volumes of flame retardant material needed," Caroline Braibant, secretary-general of the International Antimony Association, told Fastmarkets.

The question of whether antimony trioxide is harmful to human health was put forward in the United States by the National Toxicology Program (NTP) in 2016. 

The NTP started a cancer hazard assessment of antimony trioxide on September 9, 2016. It looked at the exposure to antimony trioxide in the workplace, when using consumer products containing antimony trioxide or when breathing contaminated air. 

The NTP study concluded on October 19, 2018, that based upon evidence of carcinogenicity from studies in experimental animals and supporting evidence from mechanistic studies antimony trioxide is reasonably anticipated to be a human carcinogen.

Yet the same study concluded that the data available from studies in humans was inadequate to evaluate the relationship between human cancer and exposure to antimony in general.

No official policy has called for the reduction of antimony trioxide consumption in Europe so far and demand growth for this specialty chemical is anticipated to remain stable in the years to come, producers and consumers at the conference told Fastmarkets. 

The use of flame retardants in buildings in China, a country known for having low requirements for flame retardancy in infrastructure, could trigger increased consumption of antimony trioxide in the future due to the growing Chinese housing market. This is yet to happen, producers and consumers at the conference told Fastmarkets. 

Fastmarkets assessed antimony trioxide, typically min 99.5% Sb2O3, prices as unchanged week on week at €6.50-6.80 ($7.40-7.74) per kg in-warehouse Antwerp and Rotterdam on Tuesday November 13.

Antimony trioxide is widely used across different consumer products, including halogenated flame retardants, plastics, rubber and textiles. Flame retardants account for 50% of the end use of this specialty chemical application. 

Global production of antimony trioxide is almost 110,000 tonnes per year, with China the largest single producer.