The following materials are used in the construction of the Box: Select maple, cherry or walnut hardwood, Stainless steel screen (the same material used in high-end cookware), Acrylic (Plexiglass) cover, nickel-plated steel pins and a stainless steel spring clip (for the cover). There is no solder (no lead or flux) used in the screen bonding. The added/optional draw pipe accessory (not necessary to use the Box) are now made of borosilicate glass (they were previously made of Acrylic).
There are no hazardous materials used anywhere in the Box, so yes, the Box is safe. None of these components or materials ever get hot enough to be of any concern.