Wetting agents in drilling fluids are crucial components that modify the wettability of rock formations and drilling cuttings, ensuring the drilling fluid can function effectively by reducing surface tension between differing phases. These agents are predominantly used in oil-based mud systems where controlling the wettability of the drill cuttings and formation surfaces towards a more oil-wet condition can significantly improve lubricity, decrease water invasion, and enhance the removal of cuttings from the wellbore. This optimization helps in preventing bit balling, sticking problems, and other issues related to poor cuttings removal. Selection of an appropriate wetting agent is critical and depends on the specific requirements of the drilling operation, including the geological formation, the type of drilling fluid used, and environmental considerations. Effective wetting agents improve drilling efficiency, reduce costs, and minimize the environmental impact of drilling operations.

Hydraulic oil categorized as "food grade" is specifically formulated to be safe for incidental contact with food products. For a hydraulic oil to be classified as food grade, it must meet certain standards set by organizations such as the NSF (National Sanitation Foundation). These standards ensure that the lubricant is safe for use within food processing, packaging, and handling areas. The specific designation "HO1" refers to a type of food grade oil that is considered safe for incidental food contact. This classification emphasizes low toxicity and a reduced propensity to harbor bacterial growth. However, it's crucial to consult specific product data sheets and certifications to confirm an oil's compliance with food-grade specifications and its suitability for your particular application.

Polypropylene (PP) is a popular plastic used in various food storage applications due to its ability to resist heat and chemicals, making it safe for microwave and dishwasher use. Typically, how long PP keeps food fresh depends on several factors, including the type of food, whether the food is raw or cooked, and the storage conditions (temperature, humidity, etc.). Generally, PP can effectively keep food fresh for a few days to a week when stored in the refrigerator. For example, it can keep raw vegetables fresh for about a week, while cooked meals might stay fresh for 3-5 days. It's crucial, however, to note that airtight sealing and proper refrigeration are key to maximizing freshness. Despite PP's durability, always check for signs of spoilage before consuming stored food. Regularly cleaning and thoroughly drying PP containers can also help maintain food freshness by preventing bacterial growth and contamination.