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Something smells wrong

Published by
World Cement,


Are lives being put at risk by conveyor belt manufacturers?

The harmful and in many cases potentially lethal substances used in industrial manufacturing processes have been a cause for concern for many years, not only amongst consumers but also among those who come into contact with them in the course of their day-to-day work. When the EU’s REACH regulation EC 1907/2006 came into force in June 2007 those concerns should have largely been dispelled. All European manufacturers (including manufacturers of rubber conveyor belts) became legally obliged to comply with the regulations relating to chemicals, preparations (mixtures), and substances used to create finished products.

Some 12 years since their introduction, conveyor belt specialist Leslie David decided to take a closer look into the impact of the regulations. It was discovered that when it comes to conveyor belts, something smells wrong in more ways than one. It appears that some belt manufacturers have chosen, either completely or at least partially, to ignore this legal requirement. Here, he explains about REACH in greater detail and why users of rubber conveyor belts for cargo transshipment need to be much more aware of the potential risks they may be taking.

REACH for safety

REACH (Registration, Evaluation and Authorisation of Chemical substances) regulation EC 1907/2006 was introduced to improve the protection of human health and the environment from the risks that can be posed by chemicals. The legislation compels all European-based manufacturers to register the use of ‘substances of very high concern’ that are listed within the regulations with ECHA (European Chemical Agency) headquarters in Helsinki. Incidentally, in the event of a no deal, the EU REACH regulation will be brought into UK law by the EU (Withdrawal) Act 2018.

What are the risks?

There are two primary areas of potential risk relating to the end-users of rubber conveyor belting. Firstly, those that work with conveyor belts are coming into regular contact with rubber that contains unacceptable levels of potentially harmful chemicals, including those believed to cause various forms of cancer. This especially includes conveyor maintenance operatives and the vulcanisers who fit and splice belting.

The second area of risk is to the environment itself including wildlife. The disposal of used belting has long been a headache for end-users. It is virtually impossible to regulate and control disposal but if the harmful, damaging element of the used products, in this case rolls of conveyor belt, can be minimized then that would be a huge step forward.

Who does REACH apply to?

REACH applies to all European-based manufacturers and all products sold and used within the EU. Manufacturers established outside of the EU are not bound by the obligations of REACH, even if they export their products into the customs territory of the EU. They are, therefore, free to use unregulated raw materials and chemicals that may be prohibited or have usage limitations within the European community. Significantly, as the EU-destined product itself is not exempt from REACH, it is the importers of products manufactured outside of the EU who are responsible for fulfilling the requirements of REACH, rather than the original manufacturers.

A large proportion of REACH unregulated belting sold in Europe is imported from Southeast Asia by traders. This raises a number of questions concerning human and environmental risk exposure. First and foremost, end-users are effectively required to rely on the honesty and integrity of the trader who, in turn, is reliant on the honesty and integrity of a manufacturer, who is not actually subject to the regulations. European conveyor belt manufacturers could also justifiably argue that they are at a disadvantage. This is because hazardous chemicals that would otherwise be banned entirely, or at least restricted, are used to accelerate the vulcanisation process in order to reduce production time, which ultimately creates a price advantage based on illegal practice.

Interestingly, but somewhat worryingly, with what seems to be only one notable exception, all European-based belt manufacturers import and resell belting to supplement their overall output and allow them to be more competitive on price. Again, the vast bulk of these imports come from China and to a lesser extent India. They are then sold under the European manufacturer’s brand. Anecdotal evidence suggests that, in some cases, such reselling is supported by certificates of origin that indicate Europe as the source of origin, apparently on the basis that the belting was at one stage warehoused in Europe.

A chemical cocktail

So exactly what are the potentially dangerous materials used in modern-day conveyor belts? Nylon, polyester, and steel cords are most commonly used to form the ‘carcass’ of the belt. These materials are contained within the belt and are not seen as posing a risk in their own right. Apart from PVC covered belts, which are mostly used for underground mining, rubber is most commonly used to cover and protect the carcass. Although rubber in its natural form (NR) presents little or no risk, the fact is that most of the rubber used in conveyor belting is synthetic.

The simple reason for this is that modern-day conveyor belts have to deal with a multitude of different demands, including abrasion, heat, oil, ozone, fire, sulfur, and much more – much of which natural rubber usually cannot adequately cope with. Consequently, there are literally hundreds of different components that are needed to create rubber compounds that, once vulcanised, are able to meet the specific physical performance and safety requirements.

The manufacture of synthetic rubber involves several chemical compounds that are toxic to man. The principal chemicals used in the manufacture of synthetic rubber are butadiene, which is also known as methyl allene; styrene, also known as vinyl benzene; and acrylonitrile, or acrylonitryl-vinyl cyanide. In addition to these chemicals, polymerisation catalysts, such as hydrogen peroxide, sodium perborate, ammonium persulfate, or organic peroxides or peracids, modifying agents, anti-degradants, anti-ozonants (to protect against ozone and UV exposure) are also used.

It is worth bearing in mind at this stage that the use of chemicals in the rubber compounds used for manufacturing conveyor belts is both essential and unavoidable. One such example is N-cyclohexyl-2-benzothiazole sulfenamide (CBS), which is fully allowed within the regulation. However, the big issue is whether manufacturers are continuing to use prohibited chemicals and/or are failing to apply the maximum usage levels restrictions specified within European REACH regulations.

Smelling the difference

One of the most contentious issues involving conveyor belt manufacture is the use of short-chain chlorinated paraffins (SCCPs). REACH regulations stipulate that SCCP’s should either not be used at all or at least only used on a very restricted basis because of their category 2 carcinogenic classifications. They also pose a threat to the environment, which is why they are also subject to the Persistent Organic Pollutants Regulation in the EU.

SCCPs are most commonly used in Asia, where their use effectively remains unregulated. Their presence can usually be identified by the unpleasant smell of the rubber. According to rubber compound experts, good quality rubber usually has very little smell, whereas low quality belts containing questionable levels of hazardous chemicals, such as SCCPs, often produce a highly pungent aroma. In other words, you can literally smell the difference!

An offer you cannot refuse?

The influence of raw material costs on the selling price is highly significant. Although there can never be a fixed formula, due to the wide variety of individual belt specifications, a general rule of thumb is that raw materials represent some to 75% of the cost of producing a conveyor belt. Thanks to the high level of automation, the labour cost element is very low.

When faced with a price that looks too good to refuse, it is reasonable to conclude that raw materials of questionable quality have been used. The pressure to keep costs to an absolute minimum has increasingly led to the use of sub-standard raw materials and recycled rubber that can be of dubious origin. Within recycled rubber there is almost inevitably a higher risk that potentially harmful chemical substances are present.

Working safe

The application of basic safety precautions for those working with conveyor belts is a must. Firstly, it is advisable to wear gloves when handling belts. A mask should always be worn by anyone involved in actions that may cause rubber dust to be produced (such as grinding during the preparation of splice joints, for example), to prevent the inhalation of dust particles. Washing your hands thoroughly before eating, drinking, or smoking is also very important.

A clear and present danger

Although Brussels can often be accused of over-zealous regulation, the use of potentially harmful chemicals and materials is a clear and present danger. It is not the intention of this article to scaremonger, but it is nevertheless vitally important that users of rubber conveyors in cement industry belting make themselves much more aware of the potential hazards. Therefore, it is advised to make REACH compliance a pre-requisite when choosing what conveyor belts to buy. Always ask for written confirmation from the belt manufacturer or supplier that the product they are buying has been produced in compliance with REACH EC 1907/2006 regulations.

Read the article online at: https://www.worldcement.com/special-reports/02102019/something-smells-wrong/

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European cement news Cement news 2018