The most common term is toxic workplace or hostile work environment. If you just mean a place that is hard to work in, you could also say challenging work environment or difficult workplace.

Common options

  • Toxic workplace : a negative, unproductive atmosphere.
  • Hostile work environment : a workplace with harassment, intimidation, or mistreatment that makes work difficult.
  • Dysfunctional workplace : a place where systems or relationships do not work well.
  • Stressful work environment : a place that feels overwhelming or demanding.

Best word to use

For a casual sentence, “toxic workplace” is usually the most natural choice. For a more serious or legal context, “hostile work environment” is more specific.

TL;DR: Most people would call it a toxic workplace.