From Wikipedia, the free encyclopedia. Phototoxicity, also called photoirritation, is a chemically induced skin irritation, requiring light, that does not involve the immune system. It is a type of photosensitivity. The skin response resembles an exaggerated sunburn.
The contribution margin ratio is the difference between a company's sales and variable expenses, expressed as a percentage. The total margin generated by an entity represents the total earnings available to pay for fixed expenses and generate a profit.
Contribution margin is the intermediate profit that appears on variable costing income statement, while gross profit margin, which equal sales minus all product costs (direct materials, direct labor and manufacturing overheads), appears on absorption costing income statement.