Osmolar gap without anion gap acidosis is commonly associated with which substance?

An osmolar gap without an anion gap acidosis is typically associated with isopropyl alcohol. Isopropyl alcohol ingestion leads to an increase in the serum osmolarity primarily due to the presence of isopropanol, which is capable of causing an osmolar gap while not producing significant metabolic acidosis.

When considering this scenario, isopropyl alcohol does not metabolize to produce organic acids, which is why the anion gap remains normal. In contrast, substances like ethylene glycol and methanol do result in the production of organic acids upon metabolism, leading to both an increased osmolarity and an anion gap metabolic acidosis. Aspirin can also cause a mixed picture with an increased anion gap metabolic acidosis, further differentiating it from isopropyl alcohol's typical effects.

This characteristic of isopropyl alcohol ingestion makes it a common scenario in cases where a patient presents with an unexplained osmolar gap but without the associated anion gap acidosis, thereby making it the correct answer.