The 90-day toxicity test is described as which type of study?

• A. Repeat exposure
• B. Acute dosing
• C. Subchronic
• D. Chronic

Answer: (A)

The key idea here is how toxicology studies are classified by how long and how repeatedly a substance is given to animals. A 90-day toxicity test involves daily dosing over about three months, capturing effects that develop with ongoing exposure but not long enough to be considered chronic. That makes it a subchronic study: an intermediate-duration, repeated-dose assessment used to identify potential toxic effects and target organs before longer-term studies.

Why this fits better than the other options: acute dosing refers to a very short exposure, usually a single or limited number of doses, with effects assessed soon after; chronic testing involves much longer durations, typically months to years, to identify toxicity that emerges with long-term exposure; and “repeat exposure” is a vague descriptor that doesn’t specify duration or regulatory category. The 90-day schedule aligns with the standard subchronic framework.