Clinical waste is weighed at collection, per bin, per ward, because the trust is billed on it and the figures are audited under the waste regulations. Ward 6's sharps bins come out four kilos over what the stock they use can possibly account for.
I am a waste and sustainability officer for an acute trust. Nine years.
How the weighing works, because the figures are better than most people assume.
Clinical waste leaves in wheeled bins and sharps containers. The contractor's vehicle has a weighing system on the bin lift, and each bin is scanned by its barcode and weighed as it goes up, and that pairs a weight with a ward.
We are billed on it and we report it, so the figures get checked. I reconcile the contractor's data against our own monthly.
Sharps are the easiest stream to predict. A sharps container is a rigid box, and what goes into it is needles, syringes, cannulae and ampoules, and all of those are stock items that are ordered and issued and counted.
You can work out what a ward's sharps waste should weigh from what it used. Not exactly, but within about ten percent, and I do it every year for the waste minimisation report.
Ward 6 comes out four kilos over on every sharps container.
A full container is about seven kilos. Ward 6's are eleven.
Four kilos is not a rounding error. It is more than half the weight of the thing again, on a stream that is the most predictable one in the building, and it has been that way on every collection since I started looking in 2019.
Ward 6 is a twenty eight bed medical ward with an ordinary case mix and it uses ordinary amounts of everything. Its consumable ordering is unremarkable and I have been through three years of it line by line with the procurement lead.
What has been checked, and the contractor has been decent throughout.
The weighing system on the vehicles, which is calibrated annually and which I have watched being checked with test weights.
The barcode pairing, in case ward 6's bins were being scanned and another ward's weighed. We hand marked bins for a month and stood at the loading bay.
The bins themselves, in case ward 6 had a batch with a heavier moulding. Same supplier, same model, and I weighed eleven empty ones at the loading bay on a parcel scale.
And the contents, which is the part nobody enjoyed.
A full sharps container from ward 6 was opened at the contractor's site in 2022 under controlled conditions, with two of their staff and me present in the right protective equipment, and the contents tipped out onto a table into a tray, which is a thing that is done perhaps twice a year in that industry and never for a reason as thin as mine.
Needles, syringes, cannulae, ampoules and a couple of glass vials, all of them things that ward uses.
We weighed it all. Six point eight kilos of contents and a nine hundred gram container.
The container had weighed eleven point one kilos on the lorry that morning.
What that means and how carefully I want to say it.
The bin was weighed by a calibrated system at seven in the morning and by us at two in the afternoon and the numbers differ by three and a half kilos. Nothing came out of it in between: it was sealed, it has a one way aperture and a locking lid, and it was in a cage.
We weighed the sealed bin again on their platform scale before we opened it.
Seven point seven.
So it weighed eleven on the lorry, seven point seven six hours later, and its contents add up to seven point seven.
What I have done with that.
The 2022 exercise is written up and it is in the file and it went to the head of estates and to the contractor's account manager.
The agreed action was to keep an eye on it, in those words.
Our bill is calculated on the collection weights, so we pay for four kilos a bin that our own count says is not there. Ward 6 gets through about two hundred containers a year. That is eight hundred kilos, and at the clinical waste rate it is a few thousand pounds, which is inside the noise of a contract that size and which I have raised twice and been thanked for raising.
What I do now.
The reconciliation is monthly and ward 6 has its own line in it with a note.
The thing I stopped doing is the early collection.
I used to go down to the bay at seven when the lorry comes, because that is when you see the process working and it is the only time you can check a weight against a bin with your own eyes.
Ward 6's cage comes down on the night porter's last round, at about half five, and it sits at the bay until the lorry.
I went down at ten past six in November 2022 to mark some bins for the trial and the bay was empty of people and the shutter was down and the strip lights were on.
The cage was there. Six containers, sealed, upright, and the top one was rocking, in the way a full rigid box rocks when somebody has just put something into it and let go.