On occasion, a California slip and fall accident and injury can occur when there is no obvious hazard; the floor is dry and clean, free of any dangerous debris.  Usually, slip and fall victims of this type of injury fall allege the floor was so dangerous due to it being over polished and shiny. Modern commercial cleaning waxes can have high coefficients of friction when it is properly applied to a floor surface leaving small chance of a customer or someone slipping and falling down.  However, take the real world case as an example of the hidden hazard:

The injured person and a friend were shopping in a large supermarket chain when the injured person was injured by slipping and falling while walking toward a store display sign; just prior to the fall and subsequent injury, the injured party did not see any hazardous material on the floor and had no idea to think the floor was even slippery at all.  Yet, after the fall, he did notice in passing that the floor surface was extremely shiny and looked like it had just been highly polished by a machine. No witnesses to the injury could confirm anything related to the floor's appearance or condition nor any presence of hazardous substances.  This supermarket did maintain sweep logs and so competent witness testimony indicated the floor had been recently swept and inspected within the hour prior to the fall injury.

The injure party filed a lawsuit in California court based on a theory of negligent maintenance of the floor, and to establish the existence of the hazard, the injured party relied on her observation that the floor looked shiny and appeared to be at a very high polish level.  After the defense lawyer officially answered the injured party's California slip and fall lawsuit, some discovery was issued and the, surprise, surprise, the defense lawyer filed a summary judgment motion. This means the defense is asking the judge to dismiss the case based on certain things.  The judge in this case agreed, and so did the California appeals court!  However, here is why:  the injured party, on these facts, failed to establish a hazard.  You see, there was no offer of evidence that the floor was actually in fact slippery; in prior depositions, the eyewitnesses including the employees of the supermarket all testified that they did not see the floor look slippery or seem slippery and they had no difficulty in walking or negotiating the floor surface themselves. The California court reasoned that the mere fact the injured party thought the floor appeared shiny and slippery, or just recently polished to a high shine polish was insufficient proof that the floor was in fact unreasonably slippery.  If the slippery condition could not be seen by others, and then recognized, or even measured, then the supermarket could not be held at fault because it could not have any reasonable opportunity to take any remedial measures to abate or eliminate the hazardous condition.