Benefits have been on the decline, still decent, but incumbent operators will not enjoy the benefits of their more experienced coworkers (though benefits are still being depleted for them as well).
Depending on your location, having union representation does not mean what it once does. Most unions now seem to be just happy to even be allowed to exist, let alone try to do what they traditionally did: bargain for better benefits, wages and work environment. Be the best worker you can, and avoid politics in the workplace; the union can only do so much for you.
Work environment has been "us vs. them" for as far back as people remember. Dow has never really addressed it, nor tried to fix it. Instead of trying to foster equality (or true camaraderie), most leaders and salaried co-workers will still treat you as "bargained-for", little better than a contractor, which may be how higher Dow leadership wants it. Unfortunately, leaders prosper in environments where their workers are constantly fighting each other, as they are promoted within a few years, and can leave the plant in turmoil with no effect on them.
If you do not pass your training (in some locations, known as OEM), your position and ability to retrieve it are forfeit. Dow treats anyone who does not pass their OEM as irredeemable, blacklisted, and always on the end of the list in interviews. Once someone is in that position, even an inexperienced new employee will be considered before them, despite their years as a chemical operator in the company prior to OEM.