When you work in a Conservation Lab, you just never know what the day might bring you.

Fire extinguisher residue.

The Stacks department has nearly completed closing down the Phys-Sci Reading Room and moving the reading room’s collection into the stacks of Parks Library.  However, an unknown vandal decided it would be fun to spray the mostly-empty first level of the former Phys-Sci stacks area with a fire extinguisher, covering about half a dozen book carts laden with books in a fine, yellowish-white, powdery residue.  Upon discovering the damage, our colleagues in Stacks called Preservation immediately to find out what the best course of action would be.

Fire extinguisher residue.

The powdered residue from multi-purpose dry chemical fire extinguishers (mono ammonium phosphate) can be mildly corrosive in the presence of moisture, so it was important to clean it off the books as quickly as possible.  We determined the quickest, easiest way to remove the residue was with a soft-bristled brush and HEPA vacuum, and also recommended the books be brushed and vacuumed in place, because lifting them off the cart could cause the fine-particled residue to fall down between the pages.

It’s a relief that most of the shelving in this room was empty when the vandal struck; otherwise, given the number of books that would have been affected and the potentially corrosive nature of the dry chemical spray, this minor clean-up could have been a small-scale disaster.  And that’s not fun.

Like this Modernist poster? Click the photo to read about the WPA project (c.1936-40) "Be Kind to Books."