What is a common source of ignition in industrial environments?

Electric equipment is indeed a common source of ignition in industrial environments due to the presence of electrical arcs, sparks, and heat generated during operation. This type of equipment includes motors, generators, switches, and various types of machinery that can produce sufficient energy to ignite flammable materials in the vicinity.

In many industrial settings, electric equipment is essential for operations, but it can also pose significant risks if not properly managed. For instance, equipment failures, improper maintenance, or the presence of flammable vapors can lead to hazardous situations where ignition can occur.

The other options, while relevant to industrial settings, do not generally represent primary sources of ignition. Coolant systems typically help in managing heat rather than generating it. Water sources can be crucial for cooling or process needs but do not ignite. Similarly, insulation materials may contribute to fire spread but are not direct ignition sources.