Low-emitting building materials have been around for a long time, and have become standard in some areas. LEED has increased the stringency of its emissions criteria, but these moves have largely reflected industry trends. The credit requirements in LEED v4 are also quite a bit more complex than in the past, so they will require some time to figure out the first few times a team works with them. The budget method, in particular, is complicated but ultimately easier to meet than the non-budget option.
EQc4: Indoor Air Quality Assessment