This can occur only in certain cases where the chemical concentration is so volatile enough to cause some irritating sensations in your nasal canal. In most of the cases, the strong odors will simply turn off the olfactory sensors by saturating it until it cuts off signals to brain. But there are strong odorous compounds that will not only inhibit your sense of smell, but also cause several physical trauma. Beyond 10ppm, Hydrogen sulfide is one such toxic gas that will inhibit the sense of smell at first and target your nervous system totally. Anhydrous acetic acids, ammonia, the infamous Selenophenol are some other stuffs that would do a considerable damage in you.