How do you know if the sliding glass door is
safety glass or not?
There should be something etched in the glass at one of the corners. Some can be very hard to read. Some times it helps to put something darker behind the glass.
If the home was built prior to 1968, it’s very unlikely to be tempered glass, but as previously stated, it should be etched onto the glass at a corner.
Safety films are “allowed” as retrofit applications in most CA jurisdictions. The film will also have a listing label.
If you can’t find the listing, call it out for correction or verification.
Thanks for the info. Jeff & Robert.
I’ve had decent luck shining my flash light in the corners of sliding glass doors and windows to confirm etching/label.