What's Really in Conventional Laundry Detergent?
A plain-English tour of common detergent ingredients — surfactants, optical brighteners, fillers and fragrance — and what each actually does.
Founder & Editor, Mother's Toolkit
The short version
- 'Brightening' often means optical tint, not extra clean
- Liquid is mostly water you pay to ship
- Four 30-second label checks tell you most of what matters
If you've never read the back of a detergent bottle, you're in the majority. Here's a calm, jargon-free tour of what tends to be in there — and what each part is for. None of this is meant to alarm you; it's meant to make the label readable.
Surfactants — the actual cleaners
Surfactants lower the surface tension of water so it can lift grease and dirt off fabric. Common ones include SLS and SLES. They're effective and very widely used. Some people with sensitive skin prefer gentler surfactant systems — a personal preference, not a universal rule.
Optical brighteners
These aren't cleaning agents at all. They're fluorescent compounds that stay on the fabric after washing and make whites look whiter by reflecting blue light. Your clothes aren't cleaner — they're optically tinted to look brighter. Most people are surprised that's what 'brightening' often means.
Fillers and water
Powders can contain fillers that add bulk. In liquids, water itself is a large part of what you're paying to ship. That's a big reason concentrated formats like sheets took off: less water, less weight, less packaging.
Fragrance
'Fragrance' or 'parfum' can represent a blend of many components, and brands aren't always required to list each one. If fragrance matters to you, look for a full ingredient list and a fragrance-free option.
Read any label in 30 seconds
- Is the full ingredient list published, or just buzzwords?
- Is there a fragrance-free version?
- Is a real biodegradability standard named (e.g. OECD)?
- What's the true price-per-wash, not the pack price?
Victoria's tip
Those four checks tell you more than any front-of-pack claim. They're exactly what I used to build the sheet ranking.
My top-rated sheet for UK & Ireland homes
On transparency, packaging, biodegradability and price-per-wash, TruWash BioPure topped my ranking.
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Comments (2)
The optical brighteners bit blew my mind. I genuinely thought 'brightening' meant cleaner. Reading my labels properly now.
Saved this to my phone for the next shop. The 30-second checklist is gold.