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.
Gross Profit Margin Ratio. Definition. Gross Profit Margin Ratio is the percentage of gross profit relative to the revenue earned during a period. Gross Profit Margin Ratio is also known as Gross Margin Percentage and GP Margin Ratio. Formula