As you said above, the NLRA protects employees from an employer's retaliation for working together to improve working conditions. Some people in this thread are implying that the working conditions that I complained about are not that bad and that, therefore, the NLRA will not protect workers who try to improve these not-so-bad conditions. I am asking whether working conditions have to meet some minimum standard of "badness" for the NLRA to protect workers who try to improve the conditions.
I hope that makes sense.
MidwestTech, the NLRB issued an Opinion on January 11, 2019, explaining "concerted activity," and revising and clarifying what qualifies as protected activity.
Your online comments would not be protected comments under the new ruling (or likely under the old). Your online comments were not designed to improve employee working conditions by bringing employees together to focus your employer's attention on the conditions. You were, instead, just complaining to random others about your working conditions.
Here is a link to the NLRB decision in
Alstate Maintenance, LLC and Trevor Greenidge:
https://www.managementmemo.com/files/2019/01/Alstate-Board-Decision.pdf
OSHA
has addressed employee complaints about extended or unusual workshifts (and resulting employee fatigue), and OSHA has addressed employee complaints about standing too long. OSHA agrees with you that both long hours and standing too long can increase employee injuries and illnesses in the workplace. These are factors considered to be "ergonomic stressors."
OSHA's recommendations to employers have included providing extra breaks and adding anti-fatigue mats to areas where employees must stand and to rotate employee schedules or positions so no one employee is required to stand too long at a time or work too many hours without a break.
But these OSHA recommendations are not OSHA policies. They are employer guidelines only.
What
could have protected your job would have been complaints to OSHA or the NLRB, even though complaints of the sort you had probably would not have led to the forced changes in the workplace that you wanted.
Good luck with your job search.