Complex sentence: Most instances of human toxicity due to methyl salicylate are a result of over-application of topical analgesics, especially involving children, some people have intentionally ingested large amounts of oil of wintergreen.
Split into simpler sentences: Most instances of human toxicity due to methyl salicylate are a result of over-application of topical analgesics, especially involving children. Some people have intentionally ingested large amounts of oil of wintergreen.