A tender document came across my desk last spring for a four-storey office on Wenlock Road, N1. Twelve per cent of the score sat under a sustainability heading, and every question in that section could be answered with a document rather than a fact. Do you have an environmental policy. Do you use eco-friendly products. Do you offset your emissions. We scored well. So did a contractor I know for a certainty runs neat bleach through the whole of a Croydon portfolio because it is eighty pence a litre and the site managers like the smell. The tender could not tell us apart, because it never asked a question with a number in the answer. Most sustainability scoring in London commercial cleaning works this way, and the market has adapted to it precisely.

Which green claims on a cleaning product label mean something?

Three phrases appear on roughly half the trigger sprays in London janitorial cupboards, and none of them carries any legal definition: non-toxic, chemical-free, and plant-based. The first is a dose question rather than a substance question. The second is chemically illiterate – water is a chemical, and so is the citric acid in the bottle underneath the claim. The third tells you the feedstock and nothing about what the molecule does once it reaches the Beckton treatment works.

Certification marks are a different matter, because somebody outside the manufacturer has looked at the formulation.

The EU Ecolabel flower still means something for hard surface cleaners and washroom products – restricted substance lists, biodegradability thresholds for surfactants, and dosage-based testing so a product cannot pass by being weak. Nordic Swan runs tighter on some criteria. Cradle to Cradle certification covers material health and takes the packaging seriously. Post-Brexit the UK never built a replacement scheme, so British manufacturers largely kept certifying to the EU criteria anyway, which is why you see the flower on bottles that never leave Middlesex.

ISO 14001 is a management system standard. It certifies that a company has environmental objectives and reviews them. It says nothing whatsoever about what is in the bottle, and I have watched it presented in a bid as though it did.

The labels worth checking, and the one that isn’t

Ask for the certificate number, then check it against the issuing body’s register. Certification lapses. Reformulation happens. A product certified in 2019 may have changed twice since.

Ask what it replaced.

Why does the dosing system matter more than the chemistry?

A ready-to-use trigger spray is 99 per cent water shipped by road from a factory in the Midlands to a cupboard in Victoria Street, SW1E. The environmental cost sits almost entirely in that water and the plastic around it, and no amount of certified surfactant fixes the arithmetic.

Superconcentrates dosed through a wall-mounted proportioner or into refillable bottles at a satellite station change the numbers by an order of magnitude. One five-litre concentrate replaces several hundred litres of RTU. The lorry movements collapse. The plastic collapses.

There is a second effect that matters more for water quality than for carbon, which is overdosing. Operatives who free-pour from a concentrate container aim high, always, because more looks like better and nobody was ever disciplined for a floor that smelled too clean. A closed dosing system removes the decision. What ends up in the Thames Water sewer network drops accordingly, and so does the residue that makes vinyl flooring in a Brentford, TW8, business park go grey and tacky by year three.

Here is where I argue against my own invoice: if your contractor has moved you to superconcentrates and is charging you a green premium for it, they are billing you for their own cost saving. Chemical spend on a dosed site falls, often by half. The honest position is that the change should be cost-neutral to you at worst. Sustainability line items that appear on a quotation without a corresponding reduction elsewhere are a pricing exercise wearing a lanyard.

What a wall-mounted dispenser changes in the cupboard

Two things, immediately. Concentrate containers stop being decanted into unlabelled squash bottles, which is a COSHH problem before it is an environmental one. And the number of distinct products on site falls, because a proportioner unit typically carries three or four chemistries and the twelve half-used bottles behind the mop bucket lose their purpose.

Count the bottles in one cupboard on one floor. That number tells you more about a cleaning operation than any policy document it has ever produced.

Is water-only cleaning a real method or a marketing story?

Both, depending on the surface and on who is selling it.

Microfibre with plain water does remove soil from most hard surfaces in an office. The mechanism is mechanical – split filaments with enormous surface area lifting particulate into the fibre structure. For desking, glass partitions and painted surfaces in a low-soil environment, detergent adds little. Anyone who has cleaned a Hammersmith Grove, W6, meeting room glass wall with a damp cloth and a dry one knows this already.

Water-only fails on grease and fails on disinfection. A staff kitchen at seven in the evening, with butter smears and spilled milk, needs a surfactant. Washroom surfaces after a day of use need a product with an EN 1276 or EN 13697 claim behind it, and no volume of enthusiasm about ionised water changes that.

Electrolysed water and stabilised aqueous ozone occupy a contested middle ground. Both do something. Both have short activity windows, both are sensitive to organic soil load, and both get sold with efficacy data generated under laboratory conditions that resemble no office kitchen I have ever entered. They earn their place in low-risk general cleaning. They do not replace a disinfectant in a food preparation area, and any supplier who says otherwise should be asked for the test standard, the contact time and the soil loading used.

Where microfibre stops being green

Polyester and polyamide cloths shed microplastic fibres in the wash, and a commercial laundry running sixty-degree cycles five nights a week sheds a great deal. Lifespan is the lever that matters here. A cloth rated for five hundred washes that gets thrown out at eighty because it went grey has failed environmentally regardless of what the marketing said.

Colour-coded sets get binned early because staff cannot tell a stained cloth from a contaminated one. Buy fewer, better cloths and a laundry bag system that keeps them accounted for. Wash them at forty rather than sixty where the risk assessment allows it, use a filter bag in the machine, and stop using fabric softener, which coats the split fibre and destroys the property you paid for.

Ask what it replaced.

What happens to the packaging and the waste after we leave?

Compostable bin liners in a London office are, in most cases, a waste of money. Residual waste from Greater London commercial premises overwhelmingly goes to energy recovery – Edmonton, Belvedere, SELCHP – or to landfill, and a starch-based liner in an incinerator behaves like any other fuel while costing three times as much. Industrial composting requires the liner to reach an in-vessel composting facility, which requires the waste stream to be food waste, which requires segregation that the liner alone does not create.

Where a compostable liner earns its keep is in the food waste caddy, feeding a genuine anaerobic digestion or IVC route. Everywhere else it is decoration.

Refill and dilution stations for washroom soap remove a large volume of small plastic from the chain, and cartridge systems that claim hygiene benefits are defending a market position rather than a public health one for a standard office washroom. Hand towel choice is the other packaging argument tenants raise, usually in the wrong direction. Recycled-content paper towels in a properly sized dispenser, collected into a segregated stream, beat a warm air dryer on hygiene and lose to it on carbon, and the decision belongs to whoever is answering the washroom complaints.

Vehicles matter more than any of it for a London contractor. ULEZ covers all thirty-two boroughs and the City, and a fleet running compliant diesel vans is doing the legal minimum. Electric vans and consolidated delivery runs are the meaningful change, and they are expensive, which is why very few mid-sized contractors have made them and rather more have bought a carbon offset instead.

The liner question, answered flatly

Thinner liners, correctly sized, in fewer bins. Desk-side bins removed entirely in favour of central segregation points saves more plastic than any liner specification, and it is the single change most tenants resist hardest.

How do you write a tender that greenwashing can’t pass?

Stop scoring documents. An environmental policy costs an afternoon to write and proves nothing about a Tuesday night shift in Wembley.

Score evidence with numbers in it. Ask for the full product list with manufacturer, dilution ratio and certification number for every item, then check three at random. Ask for twelve months of chemical purchase data in litres of concentrate, which tells you immediately whether dosing systems exist. Ask what proportion of the fleet is zero-emission at the tailpipe and what the replacement schedule is. Ask for the vacuum specification with the filtration class and the rated input power, because a cupboard full of 1400-watt machines running four hours a night across a portfolio is a real electricity number and an indoor air quality problem at the same time.

Ask what happens to a cloth at end of life, and listen for whether anyone knows.

The question that separates them

Ask the contractor to name a product they stopped using and explain why. A supplier with a live environmental practice has a story about a floor polish that stopped performing at reduced dilution, or a degreaser they abandoned after reading the safety data sheet properly. A supplier with a marketing department has a brochure.

Ask what it replaced.

The dosing unit on the wall of that Wenlock Road cupboard cost £180 fitted and paid for itself inside seven months on chemical spend alone.