MITRA Forum Question Details

This is beyond my knowledge base. I know how to stop the mold but if it is going to remain in high humidity conditions, I suspect that it will return. In short, I will send this to someone with more experience with mold mitigation.

​If mold is growing on pastels inside a container, it's probably related to a hygroscopic component of the material (something that draws moisture from the air). Storing pastels with a dessicant like silica gel would surely help prevent this in the future, but even ordinary dry rice would probably do a pretty good job. Some pastel painters store their sticks in a tray of rice anyway, to keep them from rolling around.

To "dry clean" the outside of affected sticks, I think you could clean a few at a time in a plastic bag of table salt. You might need to do several bags organized by similar color, and sort of rub and shake the bags to abrade the affected surfaces. 

What kind of pastels? Dry or oil? How bad is the mold? If very severe you may just want to replace them and start fresh taking preventative measures from day one. Some molds produce mycotoxins and there is a chemical hazard associated in addition to the particulate hazard of the mold and spores. So gloves, respirators or good ventilation and protecting work surfaces is really important.

As a conservator, our motto is that you can't make mold go away, it's everywhere. But you can control it by keeping temperture and humidity low. Having good air circulation helps too. 

Usually, we advise to remove dry mold with a HEPA vacuum, but this isn't something most people have. Don't use a regular vacuum as you will just spread the mold around. You should be wearing a respirator (N95 or better); however, if you haven't been fit tested you will not know if you are being protected and you can't wear them over almost any kind of facial hair including stubble. 

So you may be able to remove dry mold with a brush in very a well-ventilated space outdoors. As we've discussed in earlier posts on this forum, dry pastels in particular pose their own health hazards so you really want to avoid anything that creates more dust and spreads the pastels around.

You can try wiping them down with alcohol wipes (which might be hard to come by these days) or spray with a 70% solution of alcohol (more details in the links below). Having a solution with some water in it helps make the mold more susceptible to the ethanol. You want the alcohol to be on the surface as long as your substrate can take it. Make sure you are cleaning both the pastels and their storage containers and that they are completely dry before returning them to their containers.

Check out some mold information on the AIC wiki:

http://www.conservation-wiki.com/wiki/BPG_Mold#Removing_Fungal_Growth

http://www.conservation-wiki.com/wiki/Health_%26_Safety:_Mythbusting_Mold:_Ten_Facts_You_Should_Know

Kerith Koss Schrager