Avoiding Collections Damage from Pollutants Exposure to some
volatile organic compounds (VOCs) can accelerate oxidation and
hydrolysis in collection materials, evidenced by discoloration
and other degradation. VOCs can come from external sources, such
as outside (make-up) air, and internal sources, such as copying
equipment and materials used in buildings, exhibit cases, frames
or furniture, including paint, wood, plastics, or fabrics.
Sometimes VOCs are emitted by collections themselves. Wherever
possible, exposure of collections to VOCs should be limited.
Best practices dictate that only the most stable materials be
used in proximity to collections. This means limiting VOCs known
to damage collections to the levels listed below: Table 1:
Maximum Permitted Air Pollution after Filtration (in parts per
billion)1 Sulfur dioxide: 1.0 ppb Nitrogen dioxide: 2.6 ppb
Ozone: 4.0 ppb Formaldehyde: 4.0 ppb Acetic acid: 4.0 ppb Table
2: Unstable Housing, Case, and Construction Materials2 acid-
curing silicones, sealants,