When To And Not To Use Biological Laundry Detergent

Ever thought – what is the difference between Non-Bio and Bio laundry detergent? Do they do the same job? Well, let us help you with that, as choosing the right detergent for your various wash basket items will make a big difference to how well your laundry is cleaned but, also, how long your laundry lasts!

Biological laundry detergents contain enzymes — proteases, lipases, and amylases — that are remarkably effective at breaking down protein-based stains like blood, sweat, and food. For a lot of washing, this makes them the superior choice – especially for gym wear, kitchen cloths – stuff that is really dirty or stinky. But those same enzymes can cause real problems with certain fabrics and garments.

Wool and silk are protein-based fibres. Washing them with a biological detergent is, in effect, asking those enzymes to digest the fabric itself — leading to felting, loss of softness, and structural damage over time. For these materials, a non-biological or specialist wool detergent is essential.

Similarly, biological detergents are better suited to warm or hot washes. At lower temperatures (below 30°C), the enzymes are less active and the detergent loses much of its advantage anyway. If you’re committed to cold washing for energy efficiency, you’re not getting full value from a biological formula.

So really, for your everyday laundry, such as cotton clothing, jeans, you’re better to use non-biological detergent. It will clean effectively and not breakdown the fabric over time. For wools or delicates, use a delicate liquid detergent, such as the Hand & Delicate wash by SESI (you can shop for this via our website).

There’s also the question of skin sensitivity. While the evidence isn’t definitive, people with eczema or sensitive skin sometimes find that enzyme residues left in clothing cause irritation — making non-biological detergents the cautious choice for baby clothes and items worn by those with reactive skin. Thankfully all SESI laundry products only contain the ingredients they need to wash well – there’s no unnecessary harsh chemicals in them – but still stick to gentler detergent in these examples.

The practical upshot: use biological detergent for items which really need a good clean. Use non-biological — or a dedicated specialist detergent — for everything else apart from wool, silk, delicates. You can get both fragranced and unfragranced non-bio from us in both liquid and powder detergents 🙂