Ingredient guide:
Sodium carbonate and sodium percarbonate
Most cleaning products contain a long list of ingredients, but only a few do the actual work. Two of the most useful are sodium carbonate and sodium percarbonate – compounds that have been in common use for well over a century. They are simple, widely available, inexpensive, and break down into harmless substances after use.
Sodium carbonate
Sodium carbonate (Na₂CO₃) is also sold as soda crystals or washing soda. It is a strongly alkaline salt, which makes it effective at breaking down grease and oils, softening hard water, and removing general dirt from surfaces. It works in any water temperature and is safe on most hard surfaces and standard fabrics.
It is useful for cleaning kitchen surfaces, soaking heavily soiled laundry before washing, unblocking drains when used with boiling water, and removing limescale from household appliances. It does not bleach or disinfect.
It should not be used on bare aluminium or uncoated metals, as it can cause discolouration.
Sodium percarbonate
Sodium percarbonate (Na₂CO₃·1.5H₂O₂) is sodium carbonate combined with hydrogen peroxide. When dissolved in warm water, it releases oxygen, which gives it bleaching and disinfecting properties that plain sodium carbonate does not have. It is the active ingredient in most oxygen-based bleach products.
It is effective for removing stains from laundry, whitening fabrics, cleaning washing machines and dishwashers, and removing mould from grout or tiles. It needs water of around 40–60°C to activate properly — in cold water it is much less effective.
It is not suitable for wool, silk, leather, or delicate fabrics. It should not be mixed with acidic cleaners such as vinegar, as the two neutralise each other.
On the question of eco-friendliness
These compounds are often described as eco-friendly, and there is a reasonable basis for that. Both break down into water, sodium, and oxygen — nothing toxic. Neither contains phosphates, chlorine bleach, synthetic fragrances, optical brighteners, or the petrochemical-derived surfactants found in most conventional detergents.
That said, sodium carbonate is industrially produced via the Solvay process, which has been in use since 1861. The process is energy-intensive, uses salt, limestone, and ammonia, and produces calcium chloride as a byproduct that is not always easy to dispose of. So the production footprint is not zero.
A more accurate way to put it: they cause less harm than conventional alternatives at the point of use, and their production is less chemically complex. It is also worth noting that sodium carbonate is already present in many conventional detergents as a builder ingredient — the difference is that conventional products add a range of other synthetic chemicals on top of it.