Inexpensive vacuum bags, designed to store fabrics and made from oxygen-barrier plastic, were repurposed as ambient temperature nitrogen chambers to neutralize pests on herbarium specimens. Combination t-test and ANCOVA results on data from oxygen-monitoring tablets indicated 0.1% anaerobia was maintained inside these bags for 39 days. Anaerobia below 0.3% oxygen maintained for up to 3 weeks deactivates insects, bacteria, and most molds. One or two small oxygen-absorber packets placed inside bags affected how quickly and reliably 0.1% anaerobia could be achieved and maintained. Three vs. six flushes with nitrogen had no statistically significant effect for achieving anaerobia.