Can a family do their own cremation?

Lamar Hankins <lamarhankins@mac.com> is a lawyer in Texas and a board member of the Funeral Consumer Alliance. Recently he was asked if a family has the right to cremate a body using a funeral pyre. Here is his reply:
REPLY: I’ve tried to answer this question many times, focusing on
Texas funeral law. However, I believe that my answer will apply as
well to most states.

Texas law does not contemplate such a disposition, but it does not
explicitly prohibit it. The problem is more practical — what to do
about the remaining large bones that will not be destroyed in the
fire. Those remains will need to be buried or placed in an ossuary
or mausoleum, or pulverized to be placed in a container similar to
the disposition of normal cremated remains in order to satisfy
officials who may object to the disposition.

A variation of this procedure is what is often termed “sky burial” –
the placement of a body for disposition by vultures, insects, and
bacteria. Once the bones are barren, some disposition will need to
be made for them, at least for practical reasons, if not legal ones.
If anyone finds human bones lying around, it could trigger a law
enforcement investigation, which would be a hassle no one would want.

Texas does not have a statute which says human remains can be
disposed of only by burial or cremation in a crematory licensed by
the state, nor does it prohibit disposition by freeze-drying or
dissolution by acid. If any of these methods start to catch on, new
laws may be written to regulate such dispositions.