Definition - What does Food Grade mean?
The term food grade, often hyphenated as 'food-grade', is used to describe tools, supplies, and equipment that are of sufficient quality to be used for food production, food storage, or food preparation purposes. It's also a marketing term with practical safety significance in many industries.
For example, a food-grade nutrient reservoir would be made of food-grade plastic, meaning that it's safe for storing a nutrient solution that is being used to grow edible crops. Likewise, only food-grade solutions should be used for storing your harvests, as in food-safe vacuum sealer bags and canning jars.
Food grade may also refer to diatomaceous earth (DE), which is available in two different grades, food (human grade) and non-food (industrial grade).
MaximumYield explains Food Grade
The term food grade is an adjective that means the material or product at hand is either fit for human or animal consumption, or, more commonly, is at least permitted to come into contact with food.
Food-grade should be be confused with the term 'food-safe'. For example, a food-grade substance like a plastic food storage container might not be food-safe if it becomes microwaved or is filled with boiling water. In the modern gardening industry, selecting materials that are food-safe may be just as important as selecting materials that are food-grade.
Back to the DE example, both grades of diatomaceous earth have their uses and both are beneficial for a variety of purposes. Food grade diatomaceous earth is the only grade of diatomaceous earth that can be consumed by humans or animals, used as a natural pesticide, or used in very small quantities as an agricultural anti-caking agent.
Industrial diatomaceous earth is inedible, should not be used as a form of pest control, and is used primarily in swimming pool filtration systems.
If you are growing edible crops, always make sure the inputs you are using are food grade. If the answer is not obvious in the product's marketing or labeling, dig deeper and ask questions.