Don’t I need to choose a natural product to clean sustainably?
No you don’t. People often think that natural products are safer for them and the environment and more sustainable than man-made things, but that’s a misconception. The fact is that everything on the planet is made of the same 90-odd chemical elements so dividing things into “natural” and “chemical” can be seriously misleading.
Many people are surprised to learn that the most toxic substance known isn't an industrial chemical or chemical weapon - in fact it's a natural product, botulinus toxin. Even more surprisingly, this is used safely by millions of people, in tiny doses, in the form of Botox. It just goes to show it's the dose that determines whether something will cause harm or not.
Natural substances aren't necessarily safe for the environment either. Nature produces many substances that are highly toxic to various forms of life. Pyrethrum, from chrysanthemums, and rotenone, from the roots of certain plants of the pea family, are highly toxic to both insects and fish.
Natural substances aren't guaranteed to biodegrade quickly either, and many wouldn't pass the biodegradability tests which all surfactants used in cleaning products must pass. Trees, for example, contain many substances that are both toxic to aquatic life and slow to biodegrade. So wood that's thousands of years old can be retrieved from waterlogged ground, and paper mills that process wood pulp must take great care treating their effluent to avoid harm to aquatic life.
The one way in which natural ingredients can have an advantage in terms of sustainability is that they are potentially renewable. But many other factors come into play here, and renewable raw materials are only an advantage if they are sustainably produced.
On the other hand, synthetic ingredients frequently have the edge in terms of performance - that’s why they were developed - and performance is vital for sustainability. Some of them are simply modified versions of natural molecules re-designed to perform better. Of course, even natural raw materials need some chemical processing before they become useful ingredients - just try washing clothes with coconut oil rather than the range of cleaning ingredients it can be converted into!
Manufacturers have for many years used both natural and synthetic raw materials and ingredients, selecting whichever is best for the product in question to optimize the sustainability profile across the whole life cycle.