ECHA

Arsenic trioxide used to be one of the most important chemicals used in Murano, Italy to create their world-famous artistic glass. However, the substance was included in the Authorisation List in February 2012 with a sunset date on 21 May 2015. The glassmakers had to make a difficult decision – to apply for authorisation or to substitute. They opted for the latter. We spoke to Giorgio Cipolla, Coordinator of surveillance activities at the REACH Regional System, to ask about the impact that the substance’s removal has had on the region.

Historically, Murano Island in Italy has used a large amount of arsenic trioxide (As2O3) to produce its renowned artistic glass. Indeed, in the year before the substance’s sunset date – the date by which the use of the substance is prohibited unless an authorisation is granted – 8 000 kilograms of the substance were used.

Back in 2014, we published a case study about attempts to remove arsenic trioxide from artistic glass made in Murano. Many of the glassmakers in the region are small enterprises and artisans. When the substance was placed on the Authorisation List, they had a difficult decision to make. Choosing to substitute or apply for authorisation both required resources that were already limited.

“Traditionally, each furnace had a secret recipe for their own artistic glass products. For some of these, arsenic trioxide was an essential ingredient used to refine and decolour the glass, but also to give it a finer clarity,” Mr Cipolla says.

Giorgio Cipolla. Image: Giorgio Cipolla.

 

Intermediate or not?

It was not immediately clear that the glassmakers would need to replace arsenic trioxide as they felt that the substance was being fully consumed during the chemical processing.

“Its use was considered as an intermediate by the glass trade association as the arsenic compounds are completely consumed during the glassmaking process and are no longer present in the final product,” Mr Cipolla explains.

However, the Italian Ministry of Health and ECHA disagreed and concluded that using arsenic trioxide as a refining agent could not be considered as an intermediate use.

There were a number of reasons for the glassmakers not to apply for authorisation. Firstly, most of their furnaces are small scale and not big enough to justify the costs of requesting an authorisation for such a specific use. Secondly, it was felt that it would be too difficult to apply the technical requirements for achieving an authorisation to the traditional processes in place for producing artistic glass, particularly those related to using substances of very high concern in closed cycles.

In the end, glassmakers opted to substitute the substance.

So, as no application for authorisation was submitted, Italian enforcement inspectors warned the glassmakers not to use the substance after the sunset date of 21 May 2015.

 

Possible substitutes

Once the decision not to apply for authorisation was made, the glassmakers had to find alternatives. Some substitutes for the substance had already been identified.

Two substitutes had previously been proposed: cerium oxide and ground granulated blast furnace slag (GGBS). However, they were seen to be too expensive and not always meeting the production requirements.

“While the use of alternative substances reduces the occupational health risks and improves the environment, the glass does not have the same fine clarity that is formed when using arsenic trioxide,” Mr Cipolla says.

Other alternative substitutes include a mix of antimony trioxides and nitrate or carbonates of alkaline metals. As has been their tradition, the glassmakers’ recipes remain confidential. Some companies are using the alternative chemicals, others have found a way to adjust their process so they do not need to use arsenic trioxide – the quality of the glass is a bit different, but considered acceptable. Others have stopped producing the type of glass for which arsenic trioxide was used.

 

Controlling arsenic levels

Arsenic trioxide is typically in the form of white, glassy lumps or as a crystalline powder resembling sugar. It has no odour or taste, but when it burns, it releases fumes and arsine gas, which is highly toxic.

After the substance’s inclusion in the Authorisation List, local health authorities informed the glassmakers about the suspected health concerns related to its use. Moreover, all glassmakers were invited to fill in a detailed questionnaire on the processes applied, including information about arsenic trioxide and other arsenic compounds (i.e. their specific uses, quantities in use and storage).

“The authorities campaigned to inform about the ban of arsenic trioxide and held specific meetings about the steps being taken to control it,” Mr Cipolla says. The aim was to control and be able to inspect the levels of the substance still being used and found in the environment.

Information was gathered on 300 companies producing glass in Venice. 104 companies were producing artistic glass and 18 of these (17.3 %) were using arsenic trioxide in 2014.

 

Environmental benefits

The shift from arsenic trioxide has resulted in tangible benefits for the environment. In 2013, air monitoring sampling stations had been installed throughout the Veneto region. The Veneto Environmental Protection Agency monitored the levels of arsenic in the air in Murano from June to November 2014 (before the sunset date), September to November 2015 and July to December 2016 (both after the sunset date).

The data from the environmental monitoring stations (one located in the neighbourhood of the primary school of Murano) showed a dramatic decrease in arsenic levels. The concentrations at these stations dropped from an average of 200 to 4 nanograms/m3 bringing the levels below the target annual limit of 6 ng/m3 of arsenic in the EU.

“Concerning the environmental impact, there is a direct improvement in the air quality. After the sunset date, there has been a dramatic decrease with the recorded values lower than the threshold limit allowed for arsenic in Europe. In contrast, some previous data had even shown peak concentrations above 800 ng/m3. At the same time, epidemiological studies are being done to check the wider impacts on human health,” Mr Cipolla explains.

 

Inspections continuing throughout 2017

Since December 2015, 15 inspections have been carried out to check that the substance is no longer being used.

“Inspections include checking documents and screening raw materials to detect elements of the banned substance. If arsenic is detected in quantities of more than 1 000 parts per million (ppm), a sample is taken and analysed in an accredited laboratory. If arsenic’s presence is confirmed to be higher than 0.1 %, it is a criminal offence and the regional and national authorities are notified,” Mr Cipolla explains.

“44 samples were screened and seven have been further scrutinised in the laboratory. Two glassmakers were found to still be using arsenic trioxide to produce their glass products,” he adds. The companies that have been found in breach of REACH requirements on authorisation have been imposed an administrative sanction and the arsenic trioxide has been confiscated. Since breaching authorisation requirements is considered a criminal offence, the cases have also been deferred to court.

The programme of inspections will continue during 2017 and extend to the whole Veneto region, not only Murano Island.

 

REACH as an incentive

The inclusion of arsenic trioxide into the Authorisation List forced glassmakers to find alternatives to replace the ingredient, while trying to maintain the quality of their glassware. At the same time, human health and the environment have been protected.

“We absolutely consider REACH as the best way to ensure high levels of human health and environmental protection because it gives us information on the real properties of chemicals and how to use them safely along the whole supply chain,” says Mr Cipolla.

While big companies have the resources and tools to invest in improving their processes, SMEs are in danger of being left behind as their capacity to do so is extremely limited. “Replacing substances used for centuries is not easy. SMEs naturally consider it as a burden rather than a positive thing. REACH should avoid any kind of discrimination between small and big companies by offering more support to SMEs. In this case, the smaller companies (often artisans) were faced with an emergency situation to eliminate the substance and replace it quickly while the larger companies had the capacity to analyse the situation and plan their replacements properly,” Mr Cipolla tells.

Giving better support for SMEs so they can improve the substitution process for themselves, for instance, by helping them interact with university or research centres or work more closely with expert stakeholders, could help to change this mindset.

“It could be interesting to think about a programme of incentives at European level, to help SMEs develop new ways of production and support them to preserve production like the famous fine art glass in Murano,” Mr Cipolla concludes.

Contributions to this article were provided by Giorgio Cipolla, Maria Gregio and Massimo Peruzzo from the Prevention Department of the Local Health Authorities of Veneto Region; and Gianni Formenton, Giovina Gallo, and Roberto Lava from the Regional Environmental Protection and Prevention Agency.

 

Arsenic trioxide   Arsenic trioxide (As2O3) (CAS No. 1327-53-3, EC No. 215-481-4) was used in artistic glass production as a refining agent that helped to remove bubbles. The substance was included in the Authorisation List with the latest application date on 21 November 2013 and a sunset date of 21 May 2015.

 

Text by Paul Trouth
Top image: © Meadow2007/Fotolia

 

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