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Guides · Restroom hygiene & trade standards

Commercial restroom cleaning: toilet, urinal & faucet hygiene to REFA standards.

From proper wet cleaning of toilets and urinals to surface-safe descaling of sinks and faucets and protecting delicate cement grout: here’s how professional restroom cleaning to trade standards works, why cheap cleaning powder fails, and how the four-color system keeps germs from spreading in Hamburg offices.

Last updated: September 2026 · Reading time: 8 minutes · By Jonathan Ruiz, owner of Ruiz Büroreinigung Hamburg

HACCP
Four-color system (red/yellow)
pH 1–3
Acid range for restroom porcelain
10 steps
Standardized toilet cleaning routine
100%
Our own permanent staff
Trade definitions

REFA standards for restrooms: wet cleaning vs. wet scrubbing.

In the commercial restrooms of Hamburg law firms, notary offices, and other businesses, hygiene affects health and well-being — and how professional you look to clients. For daily janitorial cleaning of restrooms, REFA’s technical committee for commercial cleaning (REFA-Fachausschuss Gebäudereinigung) distinguishes between two basic techniques:

Wet cleaning (REFA standard)

REFA definition: In wet cleaning (Nassreinigung), adhering soil is removed by hand with a wet, lightly wrung-out sponge cloth or other cleaning cloths. The remaining moisture is then wiped up with a dry cleaning or polishing cloth.

Goal & result: The item and its surface must be free of adhering soil, fingerprints, dust, and streaks. When the work is done, no moisture may remain on the surface.

Where it’s used: Daily janitorial cleaning of sinks, chrome-plated faucets, countertops and shelves, mirrors, and the outer surfaces of porcelain fixtures.

Wet scrubbing (REFA standard)

REFA definition: In wet scrubbing (Nassscheuern), firmly adhering soil is removed by hand with an abrasive scrub sponge, suitable brushes, or scouring agents.

Goal & result: The surface must be completely free of firmly adhering soil, urine scale, rust stains, and mineral deposits. It may still be damp afterward.

Important trade note: Every tool and product must always be matched to the material. Abrasive scouring sponges are strictly off-limits on faucets and acrylic.

Restroom chemicals & how they work

Toilet bowl cleaners compared: thick gel beats powder.

Supermarkets and drugstores often advertise powdered toilet bowl cleaners with a spectacular foaming effect. In the professional building-cleaning trade (Gebäudereiniger-Handwerk), however, powdered cleaner has serious drawbacks and is considered both inefficient and harmful to the environment:

Outdated & inefficient

Powdered toilet bowl cleaner

Ingredients: Acid-releasing salts, powdered alkalis, powdered surfactants, and additives.

The neutralization paradox: As soon as the powder hits the water in the bowl, part of the acid neutralizes the alkali. This produces carbon dioxide, which makes the solution foam and fizz vigorously — but the reaction does nothing at all to clean the bowl!

No surface adhesion: Powder sinks straight to the bottom of the trap. The vertical walls of the bowl, and above all the hidden underside of the rim, are practically impossible to wet or clean with powder.

Environmental drawbacks: The salts left over from neutralization put an unnecessary burden on municipal wastewater treatment plants — without removing any dirt or germs.

Professional standard

Thick gel toilet bowl cleaner

Ingredients: Organic acids (citric, lactic, or sulfamic acid), surfactants, thickeners, pH 1 to 3.

Maximum contact time: Special thickeners keep the gel clinging to vertical porcelain surfaces for an exceptionally long time, where it actively dissolves limescale and urine scale (Sinner’s circle, or Sinnerscher Kreis: time replaces mechanical effort).

Targeted rim coverage: The ergonomic angled-neck bottle lets the trained professional apply a measured dose of gel directly under the inner rim, leaving no gaps.

Resource-efficient: No ineffective fillers. At Ruiz Büroreinigung Hamburg, we use only Dr. Schnell concentrates that carry the EU Ecolabel.

By the book

The 10-step routine: professional toilet & urinal cleaning.

In routine janitorial cleaning of toilet bowls, toilet seats, flush buttons, and urinals, only a strict sequence keeps dirt from spreading and guards against hygiene risks. Our trained teams follow this 10-step routine in Hamburg office buildings:

Step 1

Preparation & supplies

Set out everything you need: a toilet brush, thick gel restroom cleaner, personal protective equipment (PPE: chemical-resistant gloves per DGUV Regel 112-195), a red cloth for porcelain, a yellow cloth for tiles, and a separate container for used cloths.

Step 2

Flush first

Flush the toilet and urinal before cleaning begins. This washes away loose residue, wets the porcelain evenly, and primes the surface to take up the cleaning chemicals.

Step 3

Apply the cleaning gel precisely

Use the angled-neck bottle to squeeze the acidic toilet bowl cleaner evenly under the rim so that it runs slowly down the inside walls. Coat urinals from top to bottom.

Step 4

Allow contact time (approx. 5 min.)

The cleaner needs about 5 minutes of contact time to break down limescale and urine scale chemically. Without this dwell time, the result falls short and you end up scrubbing more than necessary.

Step 5

Brush the inside

Scrub the inside of the toilet bowl and urinal thoroughly with the toilet brush — especially under the rim and around the trap. Then flush and swish the brush clean in the flush water.

Step 6

Lid & seat with the RED cloth

With a fresh red cloth, damp-wipe the tank or flush button, the toilet lid (top and underside), and the seat (both sides), working from top to bottom.

Step 7

Clean the outside of the porcelain

Use the red cloth to clean the entire outside of the toilet bowl and the urinals from top to bottom, including the base and concealed pipe connections.

Step 8

Red cloth straight into the laundry

A strict one-cloth rule applies: the used red cloth goes straight into the container for dirty laundry. It must never be dipped back into a bucket of water or used on anything else.

Step 9

Surrounding walls with the YELLOW cloth

Wipe splash zones on tiles, partitions, and doors with a separate yellow cloth. This cloth, too, goes straight into the dirty laundry afterward.

Step 10

Final check & sign-off

Visually check that touch surfaces are clean, shiny, and dry. To save water, the next flush is left to the next user.

Sinks & faucets

Protecting the sink area: two ironclad rules.

Sinks and chrome mixer faucets are constantly exposed to limescale, soap residue, and cosmetics. Yet many building owners complain about porous grout or ruined faucets after just a short time. The cause is almost always that two basic trade rules were ignored:

Rule 1: Always pre-wet cement grout!

The chemical risk: Conventional tile grout is cement-based. Cement is strongly alkaline and extremely sensitive to acid. If an acidic restroom cleaner is applied to a dry cement grout joint, the porous grout soaks up the acid like a sponge. The acid breaks down the cement binder; the joint turns sandy, crumbles, and stops sealing.

How Ruiz does it, by the book: Before any acidic restroom cleaner is used, we thoroughly pre-wet the cement grout on wall and floor tiles with clean water. The capillaries in the grout fill up with neutral water and repel the acidic cleaner applied afterward, keeping it at the surface.

Rule 2: Never spray directly onto faucets!

How modern mixer faucets get ruined: When restroom cleaner is misted straight onto chrome-plated or powder-coated faucets from a spray bottle, the fine spray gets into the faucet body through the gap around the lever. Inside, acid vapors attack the cartridge seals, corrode the brass components, and cause pitting under the chrome plating.

How Ruiz does it, by the book: We always spray the cleaner onto the sponge cloth or the yellow cleaning cloth — never directly onto the faucet! After a short contact time, we rinse thoroughly with clean water and buff the faucet to a high shine with a soft polishing cloth.

HACCP standard for germ control

The four-color system: protection against cross-contamination.

In modern offices, restrooms are a potential source of infections spread by touch (e.g., norovirus, rotavirus, Escherichia coli). The only effective way to keep germs from traveling from the toilet to sinks, light switches, or keyboards is a strict color-coding system with no exceptions:

Color RED

Toilets & urinals

Only for porcelain fixtures with a high germ load: toilet bowl, toilet seat, toilet lid, urinal, and flush buttons. Red cloths never leave the toilet stall.

Color YELLOW

Rest of the restroom

For sinks, faucets, soap dispensers, towel dispensers, wall tiles, shower areas, and restroom mirrors. Keeps handwashing areas strictly separate from the toilet bowl.

Color BLUE

Offices & furniture

For desks, conference tables, shelves, cabinets, windowsills, door handles, phones, and monitors in general office areas.

Color GREEN

Kitchens & kitchenettes

For sensitive food-prep areas: countertops, coffee machines, microwaves, refrigerators, and sinks in office kitchens and break rooms.

Quality assurance & damage prevention

Damage from improper methods: what budget providers get wrong.

When untrained temps or subcontractors with no trade training do the work, your restrooms face typical defects and costly property damage:

Typical cleaning & hygiene failures

Ignoring contact time: If the cleaner is flushed away immediately, dirt stays stuck in the trap and under the rim. Odors and stubborn urine scale build up.

Cross-contamination from mixed-up cloths: When the same cloths are used on the toilet and on sinks or door handles, intestinal bacteria spread throughout the office.

Streaks & smears: If faucets and mirrors aren’t polished dry, evaporating water leaves unsightly hard-water spots.

Costly damage to materials & the building

Faded & brittle plastics: Overly concentrated acids or unsuitable chlorine cleaners bleach out the pigments in toilet seats and tanks and leave the plastic brittle and cracked.

Ruined grout: Without pre-wetting, acid eats away the cement grout between the tiles. Water gets behind the tiles and causes serious structural damage.

Scratched surfaces: Using green scouring pads on faucets or porcelain fixtures permanently scratches protective glazes and chrome.

FAQ

Frequently asked questions about restroom cleaning

The five most important questions about restroom chemicals, cleaning routines, and office hygiene.

Jonathan Ruiz
Owner & managing director

Ruiz Büroreinigung Hamburg stands for careful, trade-quality cleaning, transparent pricing, and social responsibility. We are a member of the Hamburg Chamber of Crafts (Handwerkskammer Hamburg) and of BG BAU (the statutory accident insurance institution for the construction and cleaning trades). More about us →

Sources: REFA-Fachausschuss Gebäudereinigung (REFA technical committee for commercial cleaning: janitorial cleaning of restrooms) · DGUV Regel 112-195 (use of protective gloves) · HACCP guidelines for commercial restroom hygiene. Responsible for content: Ruiz Büroreinigung Hamburg, Carl-Petersen-Straße 92b, 20535 Hamburg.

Why does powdered toilet bowl cleaner foam so much if it doesn’t clean any better?

The foaming comes from a chemical neutralization reaction between the acids and alkalis in the powder once they come into contact with water. This releases carbon dioxide gas, which creates the foam. The foam itself has no cleaning effect whatsoever — it uses up valuable active ingredients and loads wastewater treatment plants with salts. On top of that, powder doesn’t cling to vertical walls or under the rim.

Why does cement grout need to be pre-wetted before acidic restroom cleaners are used?

Cement-based grout is naturally alkaline and absorbent. Dry grout draws acidic restroom cleaner deep into the joint through capillary action. The acid dissolves the cement binder, so the joint becomes porous, turns sandy, and starts to leak. If the grout is thoroughly pre-wetted with clean water first, its pores are already saturated with water and the acid can’t penetrate.

Why should restroom cleaner never be sprayed directly onto faucets?

When cleaner is sprayed on directly, the fine mist gets inside the faucet through the gap around the lever. The acids it contains destroy seals and corrode the delicate mixing cartridge. Undiluted drops of acid can also cause pitting and dull spots on the chrome-plated surface. The cleaner always goes onto the cleaning cloth or sponge first.

How does the four-color system work in restrooms?

The four-color system assigns each area a fixed color for cleaning cloths and buckets: RED is used only for toilet bowls, urinals, and toilet seats. YELLOW covers the rest of the restroom, such as sinks, faucets, tiles, and mirrors. BLUE is reserved for office furniture, GREEN for kitchenettes. This significantly reduces the risk of germs spreading from the toilet area to sinks or desks.

What’s the difference between wet cleaning and wet scrubbing under REFA standards?

In wet cleaning, adhering soil is loosened with a damp cloth, and the moisture is then removed completely with a dry polishing cloth — leaving the surface streak-free and dry. In wet scrubbing, firmly stuck residue or buildup is removed mechanically by hand with abrasive scrub sponges, brushes, or scouring agents; the surface may still be damp afterward.

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