What is a primary risk of exceeding the recommended PPO2 limits?

Exceeding the recommended partial pressure of oxygen (PPO2) limits poses a significant risk of oxygen toxicity, which can manifest in various neurological and respiratory effects. When divers breathe oxygen at pressures greater than what is considered safe, the oxygen can become toxic to the central nervous system and other bodily systems. This toxicity increases the likelihood of severe complications, including seizures, impaired vision, and consciousness impairment.

In diving contexts, this can lead to hazardous situations, especially if a diver experiences a seizure underwater, which could result in panic, loss of buoyancy control, or drowning. Thus, maintaining oxygen levels within established limits is crucial for ensuring safety and preventing these life-threatening conditions.

The other options touch on various dive-related risks but do not directly correlate with the specific dangers arising from elevated PPO2 levels. Decreased buoyancy control, hypothermia, and dehydration are all important safety considerations for divers, yet they are not primary concerns associated with the effects of oxygen toxicity.