The storage location and conditions must be chosen so that water and impurities cannot contaminate the lubricant. The storage location must be sheltered from rain and as little subject to changes in temperature as possible. Changes in temperature may cause condensation in containers that are not tightly shut. It is best to store barrels on their sides or bottom-up so that the fill hole is below the oil level. Products sensitive to freezing, such as metal working emulsions and detergents must be transported and stored safe from freezing. Official guidelines and regulations must be followed when handling lubricants, oils and chemicals. For more detailed product-specific information, see the safety data sheets.