Those conventions and their implementation within various countries or states articulate the relationship and responsibilities of individuals with respect to that country or state, and so aren't intended for corporations. This is an area of active work. The UN Secretary General mandated that work to John Ruggie, and he has produced an initial report. There's further work going on. What does exist—and it is part of the government strategy—is the Voluntary Principles on Security and Human Rights, together with the Equator Principles, which EDC has adopted.
On October 20th, 2009. See this statement in context.