1. Tashmishei kedushah are objects which serve a holy object (such as
    a Sefer Torah), They contain a holy object or cover it and are in immediate
    contact with it. The law of tashmishei kedushah applies even to objects
    which are used more to protect than to show respect for a holy object (e.g.
    the ark in which a Sefer Torah and other sacred writings are placed, even if
    they are printed rather than handwritten by a scribe. According to most poskim,
    sacred texts that are printed have a sanctity comparable to the handwritten
    text.). Ornaments that are placed upon a Sefer Torah are also considered
    tashmishei kedushah
    even though they do not actually touch the Sefer Torah
    itself.
  2. Tashmishei kedushah that are worn out and unsuitable for further
    use must be put aside in a safe place. It is forbidden to use them for any other
    purpose and it is forbidden to burn them. The prohibition to burn them is implied
    in the verse “Do not do so to Hashem, our G-d.” In contrast, tashmishei
    mitzvah do not have kedushah after the mitzvah has been done.
  3. Mezuzah cases and paper or plastic which is wrapped around it are considered
    tashmishei kedushah.
  4. The law of tashmishei kedushah applies only to objects that have
    been designated and used as tashmishei kedushah. The law of tashmishei
    kedushah
    does not apply to objects that have been prepared or separated
    for used as tashmishei kedushah, but have not actually been used. It
    also does not apply to objects that have been used only once as tashmishei
    kedushah
    and have not been designated for use as tashmishei kedushah.
    For example, the brown paper that is used to wrap a Torah book for mailing has
    no kedushah. But if it were wrapped with that same paper with the intention
    that the paper should always cover it, it acquires kedushah and must
    be treated as tashmishei kedushah.
  5. Tashmishei kedushah such as the wrapping of a Sefer Torah, may not
    be made from something that was previously used for a mundane purpose if it
    is used in the same form in which it was used for the mundane purpose. But if
    its form is changed, it is permitted to use it. Tashmishei mitzvah, such
    as a talis bag and even the talis itself, can be made from something that was
    previously used for a mundane purpose. (Tashmishei mitzvah need not be
    placed in a geniza.)
  6. An object which serves tashmishei kedushah (tashmish detashmish),
    like the bag of a talis in which tefillin inside their bag are placed, has no
    kedushah. (The tefillin bag is considered tashmishei kedushah
    even though it does not touch the tefillin directly [they are in cases] because
    they do touch the straps.)
  7. A bookshelf that is used for sifrei kodesh is considered tashmishei kedushah
    and it is forbidden to use it for mundane purposes. It is forbidden to discard
    it or to burn it. Some allow it to be sold or to be redeemed. The bookshelf
    is no longer considered kadosh and the value of the bookshelf (the proceeds
    of the sale) is applied to purchasing sifrei kodesh.