Isopropyl alcohol is the fastest and safest way to kill fungi, bacteria and any other nasties that you may have lying around your mushroom work area. It’s cheap, abundant and can be diluted to stretch it further down to around 70%. Having said that, it has one major drawback.
It is toxic as hell. To quote Wikipedia “Isopropyl alcohol and its metabolite, acetone, act as central nervous system (CNS) depressants, and around 15 g of isopropyl alcohol can have a toxic effect on a 70-kg human if left untreated”
Although it would take a stronger stomach than most humans have to ingest that amount and keep it down. Accidental absorption through the skin, eyes and mouth on a regular enough basis could add up over time. For those of us who use it on a semi or regular basis, it’s imperative to protect ourselves against its potential danger.
I’m not saying dress up like you’re sequencing DNA… or cooking meth but look after yourself. Make sure you wear a good set of Nitrile based gloves, you can buy some by clicking here
A decent set of goggles/glasses is also a good addition, not only will it ensure you don’t get splashback or vapour in your eyes, they also provide a barrier of potential contamination to your work. I use these cheap goggles off eBay, but Amazon have a better set, exclusively for sterile work.
The most important thing I believe you need when working with Iso, especially undiluted, is an organic respirator. These masks filter out vapours and other gases and compounds other respirators are too big for. We all know that breathing in dust, spores and fumes are dangerous and yet many of us disregard Iso, thinking that it is safe.
On the odd occasion, it won’t do any harm, however, if you’re regularly working with iso in large amounts, cleaning your work area, bags and all other nasties, even with a flow hood you’re at risk. The mask I have from Screwfix was around £17.99. On Amazon and eBay they’re about the same.
It doesn’t matter which you buy, but it has to be an ‘Organic Respirator’. Face masks like surgeon’s wear are great for agar, inoculation and transfer work, but while you’re cleaning down your station and preparing it for the job you want to do, you should be wearing something more substantial even with your flow hood running. This is because your masks won’t filter out paints, solvents, resins, varnishes and adhesives whereas organic respirators will.
I’m not going to say wear a long sleeve jacket or lab coat, as much as it would or might make sense, as long as you avoid getting pure isopropyl on your skin (wash thoroughly if you do) you’ll be safe. I always wash my arms before agar work and then use ‘Hand sanitising gel’ to make sure arms are clean before I go near my work. However, something like this would probably suffice.
“Look after your body, it’s the only place you have to live”
Not only does diluting iso to 70% save money, it oddly actually makes it MORE effective as a disinfectant. This is because the chemistry that does the killing requires water as part of the reaction.
The rule is:
Using it as a solvent for cleaning, or using it on moisture sensitive items: 95-99.9% iso.
Using it as a biological disinfectant: 70-90% iso.
That’s some really useful advice! Thanks Tom!