I am sure others would include additional programs in the definition, but I think that anything crossing the line from providing equal opportunity to equal outcomes (ie quota programs) crosses the line of equitable treatment in the other direction.
Also, I'm not sure how OSHA-type protections support equality of opportunity. How does removing the ability to negotiate workplace safety with one's employer create equality of opportunity? And also (more to the point), how does progressive taxation create equality of opportunity?
I think social justice is more about equality of individual justice as applied to people in different classes. I guess that's how I'd answer that.
So OSHA requires protections for low-"class" workers that rich people would do if they were doing the work... something along those lines.
Does it mean that groups (on the "social scale") are granted the same rights as individuals? I.e., make corporate [1] personhood a fundamental concept rather than a convenient interface?
The only really concrete idea I get from the wikipedia article is that an unjust government is illegitimate (without explaining what "unjust" means), and that somehow equality of outcome is desirable.
[1] By corporate, I mean any large explicitly defined group of people, not strictly limited liability corporations.