A young man in his early twenties was found dead with several cans of petroleum-based cleaners and a plastic bag by his side. Investigators made the initial hypothesis that the young man had died of asphyxiation from inhaling the volatile fumes from the cleaners. The estimated time of death was 16 hours before discovery. When the autopsy was conducted several days later, only trace amounts of volatile petroleum-based compounds could be detected in his lungs, well beneath the lethal level. Is the original hypothesis of death by asphyxiation from inhalants still valid? Explain why only trace levels would be found.