Most laundry powders, washing powder, contain bleaches, phosphates, perfumes, synthetic detergents and often enzymes too. Between them they can seriously pollute fresh water and aggravate or cause eczema and other skin complaints. Many only work well when used with hot water, which is a waste of energy.
Alternative
There are proprietary powders and liquids on the market which use little or none of these harmful ingredients. Read the labels carefully. The fewer ingredients the better, and if the products are formulated for cold-water washes and enzyme-free, better still. For hand washing, use pure soap dissolved in very hot water; add washing soda crystals if you live in a hard-water area. Some liquid laundry cleaners can be used for hand washing too. If you use washing powders, try to buy phosphate-free products and use half the recommended amount.