Safety Glasses Performance in Cold Conditions
Modern safety glasses are made with plastic materials (including the lenses and frames). These plastic materials may undergo significant changes in material characteristics under extreme temperatures.
A particular concern for safety glasses is that plastics may have an increased brittleness at extremely cold temperatures. These conditions can reduce the impact resistance of the frame in the event of an unexpected accident involving impact to the frame or lenses.
A further concern, specific to lampworking and glassblowers' safety glasses, is potential for thermal shock to the glasses: when eyewear is stored in freezing conditions, and then put immediately into service in close proximity to a hot torch flame, the rapid change in temperature could cause thermal shock to the eyewear, increasing the risk of the frame developing a crack due to uneven thermal expansion of the plastic materials.
Best Practices for Storage & Handling
To ensure your eyewear retains its safety protective function for the duration of its expected lifetime, it is recommended to not store glassblowing safety glasses in extremely cold conditions. An example could include storing the glasses in an un-heated detached workshop or shed. This concern primarily only applies to those who work in regions that experience extreme winter weather, e.g. snow and ice storms.
If your eyewear has been stored in freezing conditions, we recommend to allow the eyewear to return to room temperature before putting them into service for flameworking activities.
Customer Service Notice
Recently at VetroSafe we have received reports from two customers that had cracks develop in the glasses frame. After further review we have traced the issue to being caused by storage of the eyewear in extremely cold conditions.
For VetroSafe customers that work in a region with extreme cold winter conditions please take note of the recommendations above.
In addition to issuing these recommendations, we have also upgraded our frame material from Polycarbonate to TR-90 Nylon, which has improved physical properties in cold conditions.
Finally, we are also extending our warranty coverage to include any premature frame failure caused by exposure to extreme cold. If you believe this may apply to your product please contact us at support@vetrosafe.com.