Debbie Knight

Posts Tagged ‘lab chemicals’

Clearing the dust…

In lab safety on February 12, 2014 at 3:49 pm


Usually when we weigh out chemicals in the lab, we use a little brush to clean off the balance. But now that we work with nanoparticles, the brush is not the right tool for the job.

Nanoparticles are tiny – in our case, really tiny particles, measuring  one hundred nanometers or less in diameter.  To put their size in perspective, they are roughly the same size range as many viruses, including the common cold virus. They can are much smaller than a bacteria (one hundred to a thousand times smaller). And, in terms of a typical human hair, you would have to line up a thousand or so nanoparticles (each one hundred nanometers in diameter) to span the width of a human hair.

When we weigh nanoparticles, they are like a really fine dust.

And this dust doesn’t really clean up very easily, at least with a brush.

So, we’ve resorted to using small squares of Swiffer Dusters™ dusting cloths.


And let me tell you, they work great!

And not just for cleaning up nanoparticle “dust.”

It works great for cleaning up standard lab chemicals as well – especially dyes like crystal violet which are notoriously difficult to clean off an analytical balance. I’ve weighed this dye out, thought I’d cleaned the balance thoroughly, only to find I hardly made a dent in cleaning it up.

I can’t believe my lab didn’t discover these little gems earlier!

Swiffer Dusters™ dusting cloths, not just for house cleaning any more.

Photo of the week

In photo log on February 1, 2012 at 9:00 am

This is a photo of chemicals sitting on a laboratory shelf in a lab that I am helping to clean out (the researcher left the university abruptly).

There are several things to note about the chemicals in this lab (especially in this photo).

  • This is an example of how not to store chemicals safely (at least according to my university’s regulations). Why? These chemicals are stored alphabetically without regard to their hazard designation. While it makes the chemicals easy to find, it is oh so wrong. The chemicals should be separated according to their specific hazard categories — category I chemicals should not be stashed next to category IV chemicals, acids should not be stored next to bases, etc.
  • As I made an inventory of the chemicals, I noted that most of the chemicals were purchased from Sigma Chemical Company.  The same is true of my lab. I’m not sure why — is it Sigma’s expansive catalog of chemicals? The company’s reputation? I’m not sure.

Some of these chemicals will be redistributed to other researchers — some in our department and some through the university’s chemical redistribution program (which helps reduce the cost of research by redistributing unwanted chemicals from one university researcher to another — kind of a chemical swap meet).

However, most of the chemicals in this lab do not have a date indicating when they were received (or their “age”).  This means we cannot be certain that the more reactive chemicals have not changed over time — reacting with oxygen or moisture in the air, for example. These chemicals will be disposed of by the university’s Environmental Health and Safety.