Contract negotiations between school Districts 158 and 300 and their respective teachers’ unions are at critical places.

Teachers in Huntley-based District 158 are discussing whether to declare a formal impasse in their talks with the school board. Teachers in Carpentersville-based District 300 declared an impasse last week.

Under state law, declaring an impasse is the last procedural move required before a teachers union can decide to strike. When an impasse is declared, both sides are required to turn over their final offers to a state education labor board, which can make the offers public. A union legally can strike 28 days after an impasse is declared.