Auto-room sterilisers, how good are they?

Pensive doctor in mask
There’s too many billions of harmful germs around to takes chances with

It’s becoming a media stampede.

Scary pictures of medics like spacemen. Panic headlines about killer diseases – Ebola, MERS and Lassa fever.

How safe are we? Are we all going to die?

Scrub, swab, rinse

Out with the bucket and sponge, heavy on the bleach. Don’t let those killers get to us.

They can’t can they?

Except, all those masks and overalls…

Maybe our wipe-clean disinfecting doesn’t go far enough. Shouldn’t we do more? We’re safe enough here in the UK, but what about flu and norovirus – aren’t they contagious and airborne too?

Which brings us to how to protect ourselves.

Fumigation. Like they do for rats and cockroaches. The whole house shrouded in plastic, everybody out for a week. A bit radical though, isn’t it? Like we can’t do it every week.

So how about the alternatives?

There are a lot of good ones.

Vital protection

Cheapest and quickest is a disinfecting aerosol “bomb”. Disinfecting, not sterilising, but it does clobber most of any germs present – airborne and surface.

Shut the windows and doors, put the aerosol in the middle of the room, hit the button – and leave. An aerosol fog of ammonium chloride is released, filling the room like bathroom steam. Any viruses or bacteria are oxidised to nothing. Twenty minutes and you’re done.

Sort of. Because – heavier than air – the fog can’t get everywhere. Nor can it reach into crevices and corners. It does a “general ” disinfect but that’s it.

There could still be germs lurking in the shadows – and probably are. There’s nothing to get the stuff under things or behind them. But hey, it leaves a nice fresh smell – so at least you’re safer than you were.

Ultra violet, ultra effective

More serious are the “zappers”. Impressive pieces of kit that generate ultraviolet light. UV is deadly to viruses and bacteria, destroying their DNA. Just a few seconds of exposure and boom – they’re gone.

These sterilisers are not small – about the size of an office photocopier – and just as unwieldy. OK to move around in the same room, but a bit of a mission to trundle round a whole building.

Satisfyingly high-tech though.

Programmable to select room size, radiation dose and duration – with remote control so they can be operated from outside. You don’t want to be present when those UV rays start bombarding – not good for the body, or soul.

Very effective though. Done in five minutes. All surfaces, and the air too.

Which means for a room with high turnover, a dental surgery say, it’s a quick way to blitz an operating room between patients straight in off the street. Familiar territory for dentists too, they’re already used to vacating the place while they take X-rays.

There is a downside though.

Like all light, UV rays only work on line of sight. Anything the light generator cannot “see” is not exposed. Germs breeding in that location are not destroyed.

Which means the back side of objects, the sides that face away from the machine. Behind the beds, the desks, the cupboards, the chairs. Half the job.

In bigger rooms there’s a fall-off effect too. The further away from the light, the weaker the exposure. Germs can survive to infect another day.

Both problems can be reduced by re-siting the machine, and blitzing the room again. A bit of a schlep, but it gets the job done. And way more pleasant than slopping around with bleach.

High performance hydrogen peroxide

The really effective stuff though, is hydrogen peroxide (HP).

Google it every which way, you’ll find it by far the most effective at destroying germs by oxidising them. Which is why so many hospitals have these sterilisers in operation – misting the place up with hydrogen peroxide vapour is a sure way to preserve patient safety.

By any standards, hydrogen peroxide is THE BUSINESS in nailing viruses and bacteria. Contact with germs kills 99.9999% of them – down to one germ in a million, hardly measurable below that – a Sterility Assurance Level of Log 6.

But, like the zappers, there’s a downside.

To be effective – that means its kill strength – the hydrogen peroxide has to be a 12% solution, pretty potent and not exactly friendly to human metabolisms. The stuff is hazardous to handle.

Everything wet, wet, wet

It’s also wet, wet, wet – basically a dosed water vapour sprayed into the air, very much like low temperature steam. It spreads, does its job, and slowly sinks back down, leaving a layer of condensation all over everything.

For this reason there’s not just one machine but two – both about the size of an office photocopier. One to spread the stuff, the other to dry the place out afterwards. So everything is not just wet, it gets heated up too. A bit hairy on sensitive equipment, particularly anything electrical.

Nor does the heavier-than-air hydrogen peroxide spread everywhere, either. Like ammonium chloride, it can’t reach all the nooks and crannies. It doesn’t behind or under everything either. Like the steam in your bathroom, it just swirls around.

You might have a Log 6 kill rate, but the job’s not all done. Not in the darkened corners – risky with MRSA and other resistant microorganisms floating around.

And float they do. Most germs are so tiny, they could fall right through a piece of blotting paper. Except they’re lighter than air and too small to see, so they could float around for ever, maybe NEVER falling all the way to the floor.

So it’s swings and roundabouts. Plus you need a hefty bloke to manhandle these HP sterilisers around.

Another dimension

Which is where the super-whammies come in – machines that generate ionised hydrogen peroxide. (iHP).

Super technology too. Developed from the military, the first of these uses multiple spray heads mounted on tripods. Flexible tubes feed the hydrogen peroxide solution from a central spray reservoir, carefully metered by a control unit.

In the actual spray head, a whopping great arc of high voltage electricity ionises the hydrogen peroxide molecules, giving them each the same negative charge.

OK, remember your school physics? Like charges repel, right? And unlike charges attract.

Got it.

So these ionised hydrogen peroxide molecules exit the spray nozzle at speed, vigorously and actively trying to get away from each other – going seriously crazy.

Result, the hydrogen peroxide disperses faster, further, wider, longer. It gets into things, behind them, under and over. And it presses deep into cracks and crevices, still trying to get away from its brothers. Ain’t no germs going to get away from that.

There’s another dimension too, quite literally.

Ionising the hydrogen peroxide changes its state from a vapour or gas – to a dynamically different plasma – the fourth state of matter.

Whammo! It’s not like vapour any more – and a whole load of other germ killers get released too. Reactive oxygen species from the hydrogen peroxide itself of course – plus hydroxyl radicals, ozone – itself a super-powerful oxidiser, and ultraviolet – the same stuff used in the zappers.

It gets better. Because all these negatively charged particles actively hunt – and actually reach out and grab – positively charged viruses and bacteria.

World War Three in microcosm – no more nasties of any kind. They are the departed.

And there’s an even better super-whammy machine too.

The Hypersteriliser

Because it’s a whole mission setting up all those spray-heads on tripods and a bit clunky, this jobbie is an all-in-one mobile unit. And yes, we do have a vested interest in it because it’s simply the best there is – the Hypersteriliser.

Straight off, you can see some thought’s gone into it.

No fiddly castors you can never steer, like a supermarket trolley – this thing’s got big wheels like a wheelie-bin but bigger, so you can get it up and down steps without giving yourself a hernia.

It’s all integrated too. You just dial up the dosage according to room-size and the machine calculates the rest. Press one button, leave the room and 60 seconds later the fine-mist spray begins, ionised just as it leaves the nozzle.

Which highlights another plus. Ionising makes the hydrogen peroxide more effective – as we’ve seen with the other machine, releasing other high-powered germ killers. This action allows a weaker solution – 6% instead of 12% – safer to use, and able to dissipate smaller and finer.

The silver edge

This plus performance plasma also packs another punch. It includes colloidal silver, a centuries-old germ-fighter first used by the ancient Greeks.

OK, give it twenty minutes.

As the plasma destroys germs, it loses its charge and reverts to harmless water and oxygen. It also evaporates, drying before it touches anything.

That makes it safe for computer keyboards and sensitive connections – and leaves a microscopically thin veneer of silver as an antimicrobial protection barrier on every surface. Lasting protection for up to weeks.

Is there a downside?

There always is, isn’t there?

As yet, they don’t make a rechargeable battery-powered model, so you can’t take it out into a busy transport yard to do trucks, containers, or buses and trains, without trailing a long mains lead.

The same with aircraft of course – though it’s way more effective than systems requiring several truckloads of kit for the same job.

Hiking up our hygiene

Whew! It’s been quite a haul getting here – and there’s no doubt which of these options we favour. But just remember, they’re all good – and anything that reduces the germ threshold is a step in the right direction.

The more protection we can give each other – particularly in the dense and vulnerable groups modern living seems to need – schools, hotels, offices, restaurants, cruise liners, you name it, the safer everyone can be.

Just think of it – no more norovirus, no more flu.

It won’t happen of course, because to do that, we’ve ALL got to remember to wash our hands all the time.

But that’s another story.