We have our enterprise standard, see as below is translate some
of the documents:
DIY: Care of Bamboo Knitting Needles
Bamboo knitting needles can dry out in overly dry climates or homes with low humidity in the winter. By contrast, they can warp in areas with high year-round humidity. They can also become rough if not used for a while. The reason for this is that the oils on your hands and in wool yarns will naturally moisturize the bamboo; if left in storage, they lack this moisture. Simply using bamboo knitting needles regularly can thus avert damage from storage.
If you do need to store needles for a sustained amount of time, do so in a climate-controlled environment. Don't store them near heaters or in the kitchen, where humidity is an issue. Keep them in a wooden box or fabric needle case (not plastic; it can encourage mold growth), in a room without extremes of dryness or dampness.
Waxing needles regularly can also keep them in top shape. Use waxed paper or the beeswax sold in sewing stores for thread conditioning on a soft cloth. Rarely will you need to sand the tips of needles, but if you do need to fix roughened points, use super-fine sandpaper and then wax the points.