In my state PT have no lunch guarantee. Many times I have worked 8 to 10 hours with only one 10 minute break. Later contracts guarantee one 10 minute break per shift when double shifting.WA CA OR all have very similar laws in this regard. The contract supercedes the state law however it's important to know that the union contract has to have specific language to override the state law. and we regulate laws through state statute similar to how we have local practices within a given Teamsters contract.
Here we follow the state laws almost to a tee except we refer PT employees to the FT contract in that lunches are taken for 8 or greater hour shifts. Some people may argue that PT do not abide by the FT contract and therefore get a lunch after 6 but this is just how it's been implemented aka makes the most sense.
It's important to know that we afford PT employees articles to the FT contract in the past when doing FT work so it's not just a one-way deal.