Several factors influence acute lethality, including: - Route of exposure: Inhalation, ingestion, dermal contact, and injection can all affect toxicity levels differently. - Dosage: Higher doses generally increase the likelihood of acute lethality. - Species: Different species may have varying levels of sensitivity to certain toxins. - Age: Young and old individuals may be more susceptible to toxic effects. - Health status: Pre-existing conditions can exacerbate the toxic effects.