We recommend that spill kits be
on site even if you think your school district does not have anymore
mercury containing equipment. One school in West Michigan was
closed for several days because a student brought in a mercury
thermometer and it broke in the school.
The Michigan Department of Environmental Quality posted the
components of a spill kit found at this
link. Here are some places to purchase the kits:

LSS has several different options, so shop around

VWR also has several options.
The MDEQ web site has other companies that have spill kits. We
have not used either of the ones we listed but found their web site to
be user friendly.