A Handy Prewash

Prewashes aren’t what they used to be. The old Preen aerosol was based on 1,1,1-trichloroethane, the solvent used in dry cleaning. So when it came to getting stains out of clothing, there wasn’t much it wouldn’t shift.

But those days are long gone. These days they are all water-based, with the main cleaning agents being enzymes and oxidisers. These are both high-performance additives which, depending on the concentrations involved, do a good job of removing food stains, vegetable and animal oils and fats, dirt, urine and other biological matter.

But they’re not so good with industrial stains – engine oil and so on.

For this, you want some Kenco:


Image result for kenco degreaser

And it’s even packaged in a spray bottle for you. Keep it in the laundry, and it’ll do a bang-up job of getting industrial oils and greases out


Shannon Lush Gets it Wrong #3

Shannon Lush is not a chemist, and in fact has no formal qualifications whatever.

We should therefore not be surprised when she gets things wrong when the topic is anything involving chemistry or, in this case, microbiology.

Yesterday on 6PR the topic of sterilisation was raised on the breakfast show. Instead of speaking to a medical or biological specialist of some sort, however, they chose to ask Shannon Lush.
Her advice was that to sterilise something it had to be in vigorously boiling water for three minutes.

This is in fact incorrect. Although boiling water will kill most pathogens, it will not kill all pathogens. And the problem is that some of the toughest bacteria to kill are also the most deadly. An example of this is Clostridium Botulinum, one of the causes of botulism, a potentially fatal disease. In fact these spores are so tough that they are often used to test a sterilisation procedure. That is, if the Clostridium Botulinum are dead, then you can be assured that everything else is.

But Shannon Lush is apparently unaware of this. The consequence of this is that if you are unlucky enough to have Clostridium Botulinum around somewhere, and you are foolish enough to follow Shannon Lush’s advice, you may finish up with botulism, a potentially fatal disease.

As anyone who has studied biology at even high school will tell you, autoclaving is required to ensure something is sterile. An autoclave is a device that will heat water to 121°C for 15 to 20 minutes. It achieves this temperature by pressurising the water, and is a standard device in any medical or biological laboratory.
I spoke with John Solvander, the program director at 6PR a few weeks ago and told him that Shannon Lush was an amateur, and that her advice was mostly wrong.

He chose to ignore this advice, however, and now 6PR has a problem. If incorrect advice is given on how to clean a carpet or shirt it doesn’t really matter that much. But when advice is given on a medical issue that is wrong, the consequence is a potential health risk, in this case a serious health risk.

I have advised 6PR of this, and that a public correction needs to be issued. They have yet to comply with this.
There are of course several simple chemical procedures that can sterilise things, the simplest being a 70% solution of metho. This is in fact what hospitals store medical instruments in. It is simple to make at home, and is cheaper than buying an autoclave.

Anyone with even the most basic knowledge of chemistry or biology would know that, but unfortunately Shannon Lush doesn’t even meet this standard.

How to Kill Wasps

This might not be as obvious as it seems.

It would be easy to treat wasps like flies, and simply spray them with a can of Mortein. The trouble with this approach, however, is that the active ingredient in Mortein, and every other insecticide on the market, is a pyrethroid.

Pyrethroids are wonderful insecticides, in that they are effective killers of insects, which have very low human toxicity, but when it comes to wasps, they have a drawback.

That drawback is that the insects go through a hyperactive stage before they die. In other words, they don’t just drop dead as soon as you spray them.
When it comes to nasty things like wasps, this can be a problem for obvious reasons. What you want is something that will disable the wasps as soon as they are sprayed.

Fortunately, this can be done. We sometimes make the mistake of thinking that poisoning is the only way to kill an insect. Now if we think about it for a moment, we can see in the world around us that there are many ways that insects, animals, and people die.

That is, aside from poisoning there is suffocation, blunt force trauma, knives and guns, drowning, heart attacks, and so on.

And so it is with insects. And in this case, the best instant killer for a wasp (or a cockroach) is an adhesive of some kind.

An example would be hairspray. Hairspray, of course, contains adhesives for sticking the strands of your head together, specifically, gums and resins.

These gums and resins are dissolved in an alcohol base, so what happens when the wasp or cockroach gets sprayed is that the solvent attacks any mucous membranes (in just the same way that pure alcohol up your nose or in your eyes will sting). This has an instant disabling effect. On top of that, the alcohol has a freezing effect as it dries, and when it does dry they find that every orifice is covered with a suffocating layer of gum or resin.

Pretty gruesome when you think about it.
But any adhesive will do. The wasps who built their nest on a water feature outside my house met their demise with a can of Kwik Grip spray. I just walked up, plastered their nest with it, and the result was both spectacular and instantaneous. Every single wasp disabled and killed immediately.

Of course, the use of any adhesive will leave sticky stuff behind whatever you spray it, but outside that it is not of course a problem