Uses and Properties
Aromatics get their name from their distinctive aromatic or perfumed smell.
Almost all aromatics come from crude oil, although small quantities are made from coals. The main substances in this group are benzene, toluene and xylenes. They are used as starting materials for a wide range of consumer products: clothing, pharmaceuticals, cosmetics, computers, paints, vehicle components, cooking utensils, household fabrics, sports equipment, etc. Products made using aromatics can reduce energy consumption and so have a positive impact on the environment.
The Aromatics Producers Association (APA) is a trade association bringing together the European manufacturers of aromatics.
Issues and Regulations
The LOA (Lower Olefins Aromatics) Consortium was formed, through which manufacturers have joined efforts to prepare by 30 November 2010 consistent registration dossiers covering 130 to 140 substances within 20 categories.
- Follow-up of the Convention on the Collection, Deposit and Reception of Waste produced during Navigation on the Rhine and Inland Waterways (CDNI) legislation on degassing of barges
- Assess the impact of the fuel legislation on aromatics producers
- Follow-up of the Common Waste Gas Treatment in the Chemical Sector (WGC) Best Available Techniques (BAT) reference documents (BREF): no quantitative BAT-associated emission levels (AEL) were determined for aromatics plants, but it could be included later in the WGC BREF
- In March 2018, the ECHA Committee for Risk Assessment (RAC) proposed in a scientific opinion to lower significantly the occupational exposure limit (OEL) for benzene in the Carcinogens and Mutagens Directive(CMD) from the previous value of 1 ppm to 0.05 ppm (as an 8 hour time weighted average). Based on their review of data, primarily from studies of genotoxicity in workers, RAC considered that an exposure limit protecting against the leading genotoxic effects of benzene, i.e. chromosomal aberrations, would also avoid exposure causing haematological suppression and other adverse effects, Based on mode of action aspects RAC considered that at exposures of 0.05ppm and below there was no significant residual cancer risk from benzene.
- To prepare for the tripartite discussion between members states, trade unions and employers, the Aromatics Producers Association (APA) together with Concawe, the fuel refining research body, commissioned Triskelion to carry out a socio-economic analysis (SEA). The study shows that reducing the benzene OEL to such an extent would be extremely costly for the industry and would be almost technically and practically impossible. The SEA Executive summary is available HERE. A SEA must be carried out to support the debate and the European Commission has mandated a consortium led by COWI, a Danish consultant, to conduct it. The industry has provided the results of its own SEA to COWI.
- Since the RAC opinion was published, a team of toxicologists and other health experts from the Lower Olefins and Aromatics REACH Consortium (LOA) has carried out more detailed work on this subject. The expert team has concluded that indeed a health-based occupational exposure limit can be set but that its assessment indicates a limit of 0.25ppm can be justified.
- The results of this analysis were first presented on 11 September 2019 at a symposium in Helsinki, organised by APA. During the symposium, Prof M. Zeegers presented the basic notions and requirements needed to ensure the quality of epidemiological studies, while Prof P. Boogaard presented the RAC opinion as it was published. S. Williams and Dr R. Schnatter presented the results of their assessment that takes into account the quality of the studies. A. Morris from DG Employment then explained the next steps in the setting of an OEL for benzene and the legislative process that should be completed by the end of 2021. The meeting was chaired by Dr. F. Faulhammer and the panel discussion was led by Dr. M. Rooseboom. The full summary of the event is available HERE.
- The expert team have now released their detailed review of the data on benzene toxicity. In line with DECOS and ECHA’s RAC, LOA proposes a health-based limit referring to threshold considerations for the toxicity of benzene. However, what is new in the LOA assessment is that the scientists in their work group have extensively reviewed the quality of all the available individual haematological and genotoxicity studies performed in workers in a structured way. This approach based on a quality assessment method has allowed to identiy the high-quality worker studies, which have been used as the basis for the Occupational Exposure Limit setting process. The use of high-quality studies define a health-based limit value of 0.25ppm (0.813mg/m3).The basis of the limit derivation and the method used for this health-based value is now published in Toxicology letters (Schnatter et al “Derivation of an Occupational Exposure Limit for Benzene Using Epidemiological Study Quality Assessment Tools”). Moreover a second paper that analysis the mode of action data for benzene toxicity and substantiates the treshhold concept has also been published in Toxicology Letter (North et al “Modes of Action Considerations in Threshold Expectations for Health Effects of Benzene”). Finally, a third paper has been submitted to Toxicology letters on the cancer risk versus exposure to benzene (North et al ; Key Event-Informed Risk Models for Benzene-induced Acute Myeloid Leukaemia).
- One factor considered by both the RAC and LOA was the potential failure to detect benzene effects on bone marrow when monitoring blood. APA, Concawe and API funded research assessing sensitivity differences in humans for detecting genetic damage in these tissues. Definitive evidence for a sensitivity difference was not found, but methods to detect a potential difference were identified (Albertini and Kaden, 2020). This work provides the basis for potential future research to resolve the sensitivity difference question.
- In conclusion, the industry believes that an OEL lower than 0.25 ppm would not provide any additional health benefits to protect workers against cancer, while forcing them to use more respiratory personal protective equipment which can increase safety risks. In addition, it would result in uncertainties about the technical feasibility and incur excessive costs for the industry. For further information, please read the industry OEL proposal and position paper.
- On 4 June 2019, the Advisory Committee on Safety and Health at Work (ACSH), a tripartite body made up of representatives from member states, trade unions and employers, approved the proposal of the Working Party Chemicals (WPC) on the benzene occupational exposure level (OEL) and advised the European Commission to adopt the binding OEL (BOEL)in the Carcinogens and Mutagens Directive (CMD). The proposal is to set a BOEL of 0.5 ppm 2 years after the entry into force of the legislation and of 0.2 ppm four years afterwards. ACSH further recommended that a revision process should be started to lower the benzene OEL even further in 2028 to take into account the 2018 RAC opinion and any new relevant information.
- In September, the European Commission published its proposal for the fourth revision of the CMD (Carcinogenic and Mutagenic Directive), which sets revised Occupational Exposure Limits (OEL) for benzene. The proposal is to set a BOEL of 0.5 ppm 2 years after the publication of the legislation and of 0.2 ppm four years afterwards. It will now be discussed for adoption at the European Council and Parliament.
- Members of APA and Concawe have developed a document to help refineries and petrochemical sites to develop an implementation plan to ensure compliance with an OEL of 0.2 ppm by 2025. The guidance document can be downloaded HERE. Both investment items and operational tems as well as monitoring are covered in the document.
- Manage research projects within the science programme. This includes the follow-up of proposed new substances into environmental regulations like Water Framework Directive (toluene)
Chair : Markus Ulrich, BASF
Vice chair : Enrico Lucchese, Versalis