Several groups have published on the gains that can be made through more detailed source segregation of wastes. Sadly, the message has generally been overstated by an insistence of a degree of fastidious segregation that cannot be sustained in practice, and ridiculous claims of annual savings that are simply scaled up estimates from the ‘theoretical’ savings noted during a day- or week-long intensive study.

Of course, none of this is sustainable since as soon as the study ends source segregation reverts almost to pre-study levels. Source segregation is, of course, an important first step in healthcare waste management, but staff have too much to do to take it to the n’th degree, and rarely is there sufficient space to accommodate the additional containers for each waste stream and sub-stream. Taking this even further, it is impossible not to stumble at the rather embarrassing contractual and regulatory restrictions placed on the waste management industries that too often sees segregated wastes concatenated for final treatment and disposal.

So we play a game of promotion, to secure ever greater source segregation. At the same time, there is the ever-present spectre of segregation errors, when hazardous or toxic or polluting waste items find their way into an unsuitable waste stream. That is rarely discussed by the protagonists, who continue to shout for better segregation performance but choose to measure and score only those wastes present in the high risk waste steams….

“Why is that piece of paper in the sharps bin?”   but not   “Why is that needle in the black sack?”

This failure to address the risks of disposal errors is a significant failure of just about every advance source segregation scheme  I have seen, and each of the publications that promote them.

There is a trend spreading quite rapidly among nurses all across America, to jump onto the environmental bandwagon and promote source segregation of clinical (medical) wastes. Each one of these is well-intentioned, and shouts of the financial and environmental savings that are achieved. How much less non-hazardous waste is in the red bag stream is the key determinant, and most often the only determinant. Measured by weight alone this does not consider quality of segregation, and by failing to sift through the black bag streams the possibility of error in segregation is ignored completely.

Source segregation is ‘good’ only if proven to be effective. Ignoring the risk assessment implication of incorrect segregation is a far too common mistake. Risk assessment must always be applied to this process, and where the risks or error are high, which it undoubtedly is, then segregation must be moderated to reduce or eliminate that risk.

For infection risks, I have previously proposed an approach where almost all wastes from clinical areas are categorised as clinical waste to eliminate the danger associated with segregation error and inappropriate down-regulation of waste items. The same would be true also for chemical and physical hazards, for confidential wastes, and for many other sub-fractions of waste.

This provides a failsafe, and potentially cost-effective, approach to clinical waste management. For several detailed reviews of how this might work see the Clinical Waste Discussion Forum archives.

Training and supervision are essential to maintain current segregation standards, with regular audit to evaluate performance. Monitoring the weight of high-grade waste or peeking into the top of an open clinical waste sack is not the way to do this and instead audit requires a detailed search through blag bag wastes. Until these systems operate effectively, further segregation options should be considered only with great caution.

I fully support the environmental advantages that can be obtained through advanced source segregation but there must be much more attention paid to what is taken out rather than what remains. Until this is achieved safely and in detail, risk assessment and the nonsense of waste regulation requirements say no, or least not just yet.

Ian Blenkharn