Hazard perception: what makes waste hazardous?

The Environment Agency has recently implemented the latest EU List of Wastes hazardous waste classifications through its Technical Guidance document WM3. This sets new criteria for defining hazardous waste and continues the seemingly inexorable rise in the types of materials accepted as a risk to human health or the environment.

Although classification provides a framework for managing high risk material, nothing is certain. Indeed, the guidance states that: ‘If there is any doubt, the worst case substance should be considered to be present’. Even where the nature of waste is more certain, there is the complication that the potential for a material to cause harm in part depends upon the context in which it arises. Clear rules are desirable in order to keep things as straightforward as possible, but oversimplification can in fact lead to inconsistencies in our waste classification system.

Hazarding a guess

While the concept of a classification system can give the impression that dealing with risk is a simple process of diverting the right material to the right disposal option, in practice handling potentially hazardous waste involves a constant assessment of risk, based on skill and judgement (as well as keeping up with new classifications).

There are constant challenges to interpretation. If an end-of-life laptop contains heavy metals, is this a hazard? From a classification point of view it is, but in terms of risk it probably isn’t (at least at the point of collection) as laptops and most other WEEE contain their dangerous materials very effectively. The result is an inconsistent approach across the waste streams, with implications for risk to human health, or conversely, unnecessary costs incurred for superfluous hazardous treatment. There is a clear financial incentive for waste producers to avoid having their waste classified as hazardous, with all of the cost implications that come with it.

Here are some other potential contradictions and inconsistencies:

• Nappies put in resident’s bins are not hazardous, but in hospitals they are often handled as clinical waste
• There is no certainty that domestic black bag waste does not contain hazardous materials, yet it is not classed as hazardous – despite the fact that dilution or mixing of hazardous waste isn’t allowed as a form of treatment in the UK.
• Animal and human material is not always classed as hazardous and yet could become an infection risk depending on how long it is stored untreated. The passage of time can increase or decrease hazardous properties (through processes such as decomposition and radioactive decay).
• A commingled collection system ‘hides’ hazardous content in the bin, avoiding the need for consignment notification to the Environment Agency, while separate collection ‘reveals’ the hazard and forces the operator to comply.
• Some chemicals are classed as acutely toxic if swallowed, while other potential poisons may go unchecked in the domestic waste stream. For example, a full bottle of whisky left in the recycling bin could surely be hazardous – for example, if found by a child.

Hazard is a complex issue not readily controlled by rules and protocols, and reading down the European List of Wastes one realises that that the system is a compromise. Many industrial wastes are in practice handled safely but could theoretically have a harmful effect. Ultimately, the misuse of any material could result in human harm. As we learn of more cases of human and environmental impacts it can seem that we are on a path to zero tolerance at the end of which all waste will become a ‘hazard’.

Classified adds

Hospitals are in effect further down the zero tolerance path, operating on the assumption that all waste is potentially infectious or at risk of misuse by patients. I recently toured a number of hospitals as part of a waste audit and witnessed a tension between the need to dispose of waste with the lowest cost and environmental impact, and the overriding imperative to avoid infection and injury. Recycling has increased in hospitals but is constrained by risk-averse practices that end up channelling some safe and potentially recyclable waste into other streams, notably incineration.

Suitable precautions: it can be difficult to gauge just how much caution is required when managing hazardous waste. Photo by the Centers for Disease Control and Prevention, via Wikimedia Commons

General municipal, commercial and industrial waste management works with the same conflicts. Hazardous waste is typically treated at a higher cost and environmental impact than other wastes, and the question arises: will the continuing reclassification of wastes as hazardous have the effect of moving huge amounts of waste down the waste hierarchy into thermal treatment and specialist landfill?

Despite the addition of new classes, there are indications that this is far from inevitable. The UK produces less hazardous waste than in the past, down from 5.6 million tonnes in 2006 to just over 4 million tonnes in 2013, according to Environment Agency Hazardous Waste Interrogator figures. During this period, which began with warnings of a UK capacity gap, we have absorbed new regulations demanding the separate management of batteries and WEEE, new restrictions on the shipment of hazardous waste, the end of the co-disposal of hazardous waste to landfill, and the 2005 List of Waste Regulations, which added dozens of ‘new’ waste types.

Loss adjustment

As well as reclassifying known wastes as hazardous, how quickly might policy makers and regulators react to newly emerging hazardous waste streams? If the case of asbestos gives a general indication of how insurance and government react to newly discovered risks, then we could be in for a long wait.

The insurance industry has reacted to many ‘new’ losses such as asbestos-related illness, but in this instance it took decades to work out where liability for compensation should be placed, partly due to the latency of the effects. Government was also slow to react, introducing legislation over a 100 year period from when the material was first identified as a health risk in the 1900s, initially in order to control the substance as a workable material and only later to deal with it as a waste.

One area insurers are taking an interest in is nano-technology. Carbon nano-tubes – used in a lightweight material with potential application in the electronics industry – are believed to exhibit similar properties to asbestos. In 2008, Lloyd’s of London published advice to underwriters suggesting they be alert to nano-technologies in general. Genetically modified material and bio-technological development have also been analysed for potential risks. These examples point to types of waste that will pose particular challenges for containment and treatment due to the fact that they operate at such a microscopic level.

Hazard is part of the lifecycle of materials through production to disposal, and will never be eliminated. Although it feels in many areas as though society is racing towards zero tolerance to risk, for waste the speed of change is relatively slow, both in terms of the emergence of new risks and the ability for those dealing with the liability (insurers and public bodies) to regulate those changes.

We’re still some way from the blanket presumption that all waste is hazardous, or a genuinely risk-based approach to classification. Common sense application of the rules remains our best guide for the time being, but needs to be backed by equally sensible enforcement in order to ensure that the financial incentives to avoid classifying waste as hazardous don’t win out over the protection of health and the environment.