Cleaning a cleanroom ’til it’s clean!

I like a clean lab. Clean labs are nice places to work – also they are slightly less likely to either kill people or cause a major environmental disaster. Both of which are bad, although I feel if the local wildlife can’t survive the chemical equivalent of a ‘Three Mile Island’ then clearly evolution has some more work to do.

My lab is a slightly lax cleanroom. I don’t run it at anything like the standard of a proper cleanroom, but it is held under positive pressure and has its own filtered air supply. I need this because lots of the monolayer and coatings chemistry I do is quite picky about dust.

For example, if a speck of dust lands on my monolayer while it is compressed, then my nice monolayer quickly collapses (with, I assume, a tiny cry of “OMG, DUST! PILE ON!!!”) – and delicate monolayer chemistry is a lot harder when the monolayer is less ‘mono’ and more ‘pile’.

But having a partial cleanroom has its benefits. The filtered air means that dust build-up is really, really slow. It can take a year to get any noticeable build-up on any surfaces. And because everyone wears booties, the floor stays pretty immaculately clean (aside from the odd chemical burn).

However, all these benefits don’t make up for the fact that cleaning a cleanroom is a massive pain in the arse.

Firstly, no hoovers. I can’t run the hover round to clean up the dust. While being pretty efficient at sucking up dust, they are almost as efficient at blowing it all round the lab. Hoovering would suck up 70% of the dust from all the hard to reach places but also make sure the remaining 30% then gets blown around my lab onto my experiments.

Secondly, no surfactants (soap). While my monolayers like to collapse when faced with tiny specs of dust, this is a minor problem compared to dust coated in any surfactants. Those won’t just bugger up my experiment they’ll coat my equipment and bugger up future experiments!

Before I worked in this cleanroom, I’d cleaned labs before but without these restrictions, so I had to come up with a cleaning routine.

My current method is to mop the floor with my ‘cleanroom ONLY!’ mop, and tap water. This gets up the dust (as well as small screws I thought I’d lost) without kicking it up into the air.

I then wipe down all the surfaces with cleanroom wipes soaked in distilled water. I use distilled water because I found tap water was leaving equally annoying limescale residues around the place. Nothing is simple!

Wiping down the surface also means I get to play ‘find the specks of weird colourful chemicals’. This is a fun game and a bi-product of all the fun colourful stuff I get to use. Over time, specks of these materials can escape and get lodged in hard to reach corners. When I wipe the surfaces and clean all these little nooks and crannies I tend to find that my nice white wipe suddenly looks like a rainbow… a rainbow made of unidentified chemicals. There’s a good reason I tend to wear my slightly thicker gloves for this step.

As I said, I kind of just made this up on the basis of it sounding like a good way of keeping it clean. If you have any actual experience of keeping a cleanroom clean, then I’d love to hear suggestions (and mockery!) in the comments below.