A patient consumed 3 grams of aspirin over a 24 hour period to treat his lower back pain. Aspirin level is 5 mg/dL. Is this toxic?

No.

Maximum recommended adult dose is 4 g/day.

Toxicity generally occurs if acute ingestion of 150 - 200 mg/kg or chronic ingestion of 100 mg/kg/day x 2 or more days.

Serum levels greater than 90 - 100 mg/dL in acute ingestion and greater than 60 mg/dL in chronic ingestion are considered dangerous.


Source

Olson, K. "Poisoning and Drug Overdose"  4th ed.

Aspirin: Drug Information.  Lexi-Comp.  Up To Date.