RH

RH is the abbreviation for relative humidity: the amount of water vapour present in the air expressed as a percentage of the maximum the air could hold at that temperature. Controlling relative humidity is fundamental in food storage and processing. High humidity encourages mould growth on grains, dried foods, and cheeses, while low humidity dries out fresh produce, meats, and baked goods, causing weight loss and staling. Warehouses, ripening rooms, and drying chambers therefore regulate RH closely, and packaging specifications often assume a defined humidity range for shelf-life predictions.