“Do you use organic products? We’ve got a baby who’s crawling now.”

I get that call most weeks, and the honest answer takes longer than the caller wants. Every solvent, every surfactant and every terpene I carry is organic in the only sense the word has in chemistry, which is that its molecules are built on carbon. So is petrol. Meanwhile the safest things in the van, hydrogen peroxide and water among them, are inorganic and would fail any test the word is being asked to apply.

That is a pedant’s answer, and I would drop it if the confusion did no harm. It does harm. It sends people towards products that smell of oranges and away from questions that would tell them something.

What does the word mean on a bottle of cleaning product?

Nothing fixed, which is the whole difficulty.

In food and in cosmetics the word is tied to certification schemes with inspectors and paperwork behind them. Nobody has ever asked me for a certificate for a carpet cleaning visit, and there is no certificate I could produce if they did. What exists instead are product ecolabels, the EU Ecolabel and the Nordic Swan among them, which cover a formulation’s toxicity and biodegradability and are assessed by somebody other than the company selling it. Those mean something. A green leaf printed on the label by the manufacturer’s own designer means whatever the designer decided.

In practice, in this trade, the word describes a price bracket and a tone of voice. The product inside is usually a competent plant-derived detergent that works about as well as the synthetic one next to it on the shelf.

There is a second reason the word travels so well in this trade. Carpet cleaning is bought once every year or two by people with no way of judging the work, and a customer standing in their own hallway cannot assess a technician’s rinse technique. So they reach for a proxy, and a word that has done honest service on a vegetable box is the proxy nearest to hand.

The orange one

d-limonene is the example I use on the phone. It is extracted from citrus peel, it is as natural as anything in the world, it is an excellent degreaser, and it is a recognised skin sensitiser that carries hazard warnings and is rated as harmful to aquatic life. I use it. It is the right tool for adhesive residue and for some greasy traffic lanes. If a customer tells me they want the natural option and I hand them a jug of orange solvent, they have got exactly what they asked for and nothing they wanted.

Is the claim dishonest, or is it just empty?

Mostly empty, and empty claims do their damage differently from lies. Nobody has to be deceived for the outcome to be bad.

The firms advertising this in London are not, in my experience, putting anything dreadful in people’s houses. They are doing a normal clean with a plant-based detergent and charging a bit more for the reassurance, and the customer gets a clean carpet and feels better about it. Nobody is poisoned. Nobody is defrauded in any way that would interest anybody.

What happens is that the customer’s one question gets used up. A person with a baby on the floor has a single real concern, which is what will still be in that carpet on Thursday when the baby is lying on it, and they spend that concern on the provenance of the ingredients rather than on the thing that determines the answer. The firm gets a sale, the customer gets a word, and the mechanism that would have protected them goes undiscussed.

What nobody in this trade can show you

An independent standard for a green carpet cleaning service. There is no inspection, no audit, no renewal, no body to complain to. Ask any London firm advertising this, mine included, to send you the scheme they are certified under, and watch what comes back. Usually it is a product brochure.

What reaches a child crawling on the floor?

Residue, and residue is a question about method rather than about ingredients.

Every wet clean puts detergent into a carpet. What decides how much stays is how thoroughly it gets rinsed out, at what pressure, at what temperature, and whether the technician bothered with a second pass. A cheap synthetic detergent rinsed properly leaves a floor with less in it than the most admirable plant-based product applied heavily and half recovered. I have followed firms into houses in Clapham and Dulwich where the carpet crunched underfoot a fortnight later, and in both cases the paperwork on the table used the word natural.

The variables that matter run roughly like this. Correct dilution, because a product at double strength leaves double the residue. Adequate dwell time, so chemistry does the work instead of volume. An acid rinse where the detergent was alkaline, to bring the pH back down and stop the pile holding a soapy film. Proper extraction with enough dry passes. Then drying, because a floor that stays damp for two days is a hospitality suite for bacteria regardless of what went on it.

Ventilation is the free part and the part nobody does. Windows open on both sides of the property for the first few hours, interior doors open, and air moving through rather than sitting. Whatever was put down goes out faster, the floor dries faster, and both of those matter more to a child on the carpet than the provenance of the detergent. I say this on every domestic job and I watch about half the households close the windows behind me because it is January.

Unscented beats fragranced every time

Fragrance is added volatile compounds, put there so the room smells the way people expect a cleaned room to smell. A properly cleaned carpet smells of nothing. If you have a child, or asthma in the house, ask for fragrance-free and accept the disappointment of a floor that does not announce itself.

Which natural products would I keep out of your house?

Several, and this is where the word does its worst work.

Tea tree oil is the clearest case. It appears in a good many natural cleaning products, and it is toxic to cats, who groom whatever they walk through and lack the liver enzymes to deal with it. I will not put it on a floor in a house with a cat, and a customer who has chosen a product because the label reassured them may have no idea it is in there.

Pine and citrus terpenes have a second problem in enclosed rooms, where they react with what is already in the air and form compounds nobody wanted. High-alkaline plant-derived degreasers are sold as gentle and will damage wool faster than a neutral synthetic detergent, because wool cares about pH and has no opinion about where a chemical came from. And the vinegar-and-bicarbonate routine that circulates online is an acid and a carbonate cancelling each other out in a satisfying fizz, after which you have salty water and a job still to do.

Boric acid deserves a line as well, since it shows up in some plant-marketed carpet powders as a moth and beetle treatment. It is a mineral, it is natural by any reasonable use of the term, and it is the one thing in this piece I would most want kept away from a crawling child. Natural and safe were never the same word, and the products that blur them are doing it on purpose.

The label tells you the story it was written to tell

Ingredients lists on cleaning products are not full disclosure, and the front of the bottle is marketing. Everything useful sits in the safety data sheet, which exists for every professional product in the country and which any supplier will hand over without argument.

What should you ask for instead?

Four things, and none of them contain the word.

Ask for the safety data sheets for what will be used in your house, and read the hazard section. Ask what the rinse is and whether the pH gets brought back to neutral afterwards. Ask how long the carpet will take to dry and what the technician will leave running. Ask whether everything can be fragrance-free.

A firm that answers those four well is giving your child a better afternoon than a firm with leaves on the van, and the answers take five minutes to give. I have lost jobs on that speech, because people ring wanting a yes to a simple question and I hand them homework instead.

What I charge for the green option

I run one, because customers ask for it and because the products in it are decent, low-odour and fine for the work. I price it above the standard clean, and when somebody asks whether it is worth the difference I tell them the truth, which is that most of the benefit they are imagining comes from the rinse and the drying and those are in both versions. Perhaps a third of them take the cheaper one. The conversation costs me about four minutes and a slice of margin each time, and I have never once regretted having it, because the customer who understands what they bought does not ring in a fortnight asking why the floor feels tacky. The rest pay the premium, which tells me something about how much the word is worth to people, and none of it is about chemistry.

In Muswell Hill a woman asked me to email her the data sheets before she would book, went through all six of them, and then asked whether I could use the unscented rinse. She is the only customer in twenty years to have done it, and she is the only one who asked a question the answer to which changed what I put on her floor.