Yes. According to Schott’s catalog, several filter glasses including BG42, UG5, UG11, BG39, S8612, S8022, and S8023 can undergo surface changes after only a few months of normal storage. Schott specifically recommends applying a protective coating or using lamination for durable use of these glasses.

For an installed UAV assembly, the practical takeaway is that bare UG11/BG39-type glass is not ideal if it will be exposed long term. A protective coating may help, but lamination is likely the more durable solution because it physically isolates the sensitive glass surfaces from the environment. If maximum durability matters, a laminated stack is the safer approach than leaving the filter exposed and planning to polish it later.

So, yes—these filters can be used outside a lab setting, but they generally should be protected by coating or, preferably, lamination when used in fixed or hard-to-service assemblies.