Australia's Science Forum

Hi
I had a phone call from the WHS consultant asking me whether the Wooden Test Tube racks are still ok to use in DET schools due to the timber being porous (after using for a number of years and the varnish has worn off) and can absorb chemical residue.

She mentioned the two tier timber shelving that was used in labs to store small reagent bottles - apparently these have been banned in DET schools for
the same reason.

Does anyone know about this? and should all timber test tube racks be replaced with plastic ones?
(I do really like the timber ones. Much sturdier than the plastic ones and hold 10 test tubes .)

Any info on this would be helpful.

Thanks Rosemary

Interesting thought. I have thought about this and have considered replacing ours but the cost, and more importantly, the wastage of just throwing them away has put me off the idea. I haven't heard anything about this otherwise. I guess to consider the situation, what do the students use that would be hazardous ie likelihood and consequences. Would getting them to rinse the racks off be a sufficient control?
They are different to your shelving - pretty sure the code of practice says to store chemicals on non-porous surfaces, but without checking I'm not 100%. But the shelves are fixed and can't be cleaned, chemicals sit on them for long period so the risk of contamination is higher than that for a test tube rack.
I think if I was setting up a new school, I would seriously consider plastic or metal racks. Until I get a definite direction (which won't happen here) I'll stick with the wooden ones. Students are often made to wear gloves and are certainly made to wash their hands at the end of the prac, so I think the risk is low.

I have revarnished some of mine that has deteriorated over the years. Definitely extended their life span.

We still have dozens of wooden ones and I've wondered the same thing about contamination .
I've seen at other schools what happens to plastic ones when hot test tubes are put in them . For that reason I will stick to our old wooden ones 'til further notice .

AnnNos , did you sand them back to wood or just re-vanish as is ?

We are slowly replacing all ours with the blue plastic ones can go through the dish washer, haven't had an issue with hot test tubes, one lab has now had them for over 4 years.

Yes I think there is a problem with years of chemical residue build up. There are a lot of chemicals student are not allowed to use anymore or very diluted solutions now. Leads and cobalt are a good example.

Anything that can go through the dishwasher on a regular basis is a no-brainer for me. Makes life easier.

Revarnished without sanding. It's a big job to sand the whole rack back to bare wood. Haven't had a single one peel back or the varnish bubble.

I have slowly replaced my wooden ones that were broken and beyond repair and the plastic ones that had been melted with the metal racks that 12 or 15 test tubes from small to large. I haven't heard anything about chemical residue on the wooden ones but it would be good to hear about