There are an estimated 20 million bikes in the UK, though it’s not clear how many are sitting in a shed in the garden and how many are actually used for regular transportation. In fact, hard facts on bike usage, production, sales, imports, exports and trade are hard to come by, and constantly changing, which means it is extremely time-consuming to assemble statistics and keep them up-to-date.
What is clear is that if you are one of the growing number of people who commutes as often as possible by bicycle, you really are doing your bit for the environment: according to the Worldwatch Institute, a short, four-mile round-trip by bicycle keeps about 15lb of pollutants out of the air we breathe. Bicycles are also more economical to make and run, since, once on the road, they require muscle power rather than fossil fuels to keep going.
Like every kind of vehicle, however, bicycles require regular maintenance to run well and be safe. In particular, your bike chain needs regular attention. An un-oiled chain suffers excess friction and, eventually, from rust, inhibiting performance and efficiency.
We have a lot of bike-riders at the Ecologist, so it came as quite a shock one lunchtime when, while doing a bit of necessary maintenance, one of them looked at the label of his can of chain lube to see the words ‘hazardous’ and ‘irritant’ alongside a giant black cross on an orange background.
Other brands seen since contain warnings such as ‘dangerous to aquatic life’, ‘dangerous for the environment’ and ‘harmful if swallowed... may cause lung damage’. On any product, such dire warnings should at least cause you to think twice before buying – and using – it.
Out of the frying pan
There are three basic types of chain lube:
¡ö Spray lubes – thinner, lighter oils that come in spray cans.
¡ö Wet lubes – slightly thicker for all weather conditions; these cope well in the wet.
¡ö Dry lubes – usually wax in a solvent mixture, where the solvent dries off to leave wax on the chain. Spray lubes, as the name implies, contain harmful propellants.
Spray lubes and wet lubes often contain Teflon (also labelled as PTFE/polytetrafluoroethylene) as well as petroleum distillates. In dry lubes, the wax is usually petrochemical-based, and the solvent, which is also petrochemical-based, can be anything from kerosene (jet fuel) to paraffin. All of these are ingredients of concern. Petroleum distillates are skin irritants and damaging to the lungs, as are propellants. But it is the Teflon that is particularly worrying. According to the Guinness Book of Records, Teflon is the world’s most slippery substance. Most of us associate this waxy, slippery, dirt-, fat- and water-repellent substance with frying pans and cooking utensils, but also stainproof carpets and clothes, paper products, fast food packaging, spectacles, as insulation on electrical wires and even the fabric roofs covering football stadiums. It’s also useful for keeping the wheels on your bike rolling. Teflon is so useful that for 50 years it completely escaped the scrutiny of environmental regulators.
And then the floodgates opened.
Teflon, which is known chemically as polytetrafluoroethylene, or PTFE, is a plasticlike substance made up of a complex mixture of perfl uorinated chemicals (PFCs). Unlike known environmental villains such as DDT and PCBs, PFCs are not generally volatile – in other words, they do not become easily airborne and so tend not to migrate long distances. In addition, to produce a substance such as Teflon, these compounds are usually ‘locked’ into polymers – chains of molecules – so it was assumed that they couldn’t leak into the environment. Even if they did, it was assumed that they wouldn’t break down; and even if they did, it was assumed that they were biologically inert. All of these assumptions are being proved wrong.
Scientific data shows that PFCs fulfil every single criterion for persistent bioaccumulative toxins: that is they do not biodegrade, they accumulate in people, animals and the environment, and they have been shown in laboratory tests to be toxic to mammals. Although there are nearly 100 known PFCs, only two have been studied in any depth: perfluorooctane sulfonate (PFOS), a breakdown product of the stain-repellent Scotchguard (now withdrawn from sale), and perfluorooctanoic acid (PFOA), a breakdown product of Tefl on. Both have been found in the blood of nearly every human tested, as well as in animals in the Arctic and Atlantic oceans.
A toxic trail
Once in the environment, PFCs have been shown to accumulate in organs like the liver, gall bladder and thyroid gland. In primates, including humans, exposure to one of Teflon’s breakdown products, PFOA, has led to an underactive thyroid (hypothyroidism). A prolonged state of hypothyroidism is a risk for obesity, insulin resistance and thyroid cancer.
Laboratory studies also show that PFOA is toxic to at least nine types of cells that regulate immune function. Cells in the spleen and thymus – both critical to immune function – are particularly vulnerable, and humans exposed to PFOA show reduced immune function. Most recently, PFOA has been linked to raised cholesterol and triglyceride (blood fat) levels in factory workers, and in animals to potentially dangerous changes in the size and weight of several important organs such as the brain, liver and spleen. PFOA is also thought to be a hormone disrupter.
In 2005, the US Environmental Protection Agency classified PFOA as a ‘likely human carcinogen’ and asked industry to work towards eliminating PFOA and related chemicals from emissions and products by no later than 2015.
The quickest way to degrade Teflon is through high temperatures. Such is the paucity of research on how it degrades, however, that nobody is entirely sure what else might cause it to break down. Or even how it, and its constituents, get into the environment. Being ‘locked’ in a cookware coating is one thing, but being sprayed on to a bike chain is another. Chain lube is not meant to stay in place for 20 years. With normal wear and tear and friction the lube will come off – even if the product contains glue-like tackifiers (which are also petrochemical-based irritants). Ride on a wet road or through a wet woodland and the lube will begin to wash away into the sewers or on to the land.
Maybe you think the chain lube is not much of an environmental priority, but it’s worth seeing the bigger picture of lubricant oils, which are widely used in manufacturing and mechanical maintenance. It is estimated that 40 per cent of all lubricants are released into the environment. Their ‘proper’ disposal usually includes either burning or being put into landfill, or recycled, each of which has its own environmental impact. Burning releases toxic soot into the air, which is a hazard when inhaled or when it lands on crops or in water supplies, and landfill runs the risk of toxic chemicals seeping into groundwater.
The Environment Agency and WRAP (Waste & Resources Action Programme) are currently running a consultation on the best ways to dispose of waste lubricant oil (though bicycle chain lube is not included in this consultation). This is primarily concerned with turning used lubricating oils into a cheaper alternative to virgin fossil fuels – lubricating oils are made from waste fuel, so returning them to fuel does complete a cycle of sorts, but it is also energy-intensive and polluting. Recycling is also problematic because of all the additives in lubricant oils.
Alternatives to toxic chain lube are not plentiful. One company, Green Oil, produces a useful biodegradable chain lube made entirely from plant-based ingredients and which is not an irritant, dangerous for the environment or hazardous. The company even goes so far as to use recycled paper for its label, while the bottle is made from HDPE, the same plastic used for milk bottles, so once you’ve run out it can be recycled – provided your local council accepts plastic milk bottles. Alternatively, the company offers customers 20p off their next purchase on returning empty bottles. So, the bottom line is to carry on wearing those figure-hugging synthetic Lycra cycle shorts if that is your preference (we’ll tackle their environmental footprint another day), but when it comes to bicycle maintenance, maybe it’s time to consider something with a lighter environmental tyre-print.
This article first appeared in the Ecologist October 2008