Final answer:
Grease on a ceiling indicates inadequate ventilation in a kitchen by failing to remove grease-laden vapors, posing hygiene and fire hazard concerns.
Step-by-step explanation:
The presence of grease on an establishment's ceiling can indeed be a sign of inadequate ventilation. When kitchen exhaust systems do not function properly, they fail to remove grease-laden vapors and heat produced by cooking appliances. This can result in grease deposits accumulating on various surfaces, including the ceiling. The buildup of grease not only presents a hygiene and aesthetic problem but also poses significant fire hazards as grease is flammable. Therefore, it's crucial to ensure that the ventilation system in a culinary establishment is functioning effectively to maintain a safe and healthy environment.