Power washing detergents fall into six main families: alkaline degreasers, traffic film removers (TFR), foaming agents (snow foam), fuel cleaners, hydraulic oil cleaners, and food fat cleaners. Each works on a different kind of dirt, so you pick by soil and surface, use the mildest mix that works, let it dwell, then rinse before it dries.
Power washing detergents come in six main types, and each one targets a different kind of dirt. If you match the detergent to the soil and the surface, you clean faster and avoid damage.
In this guide, you will learn:
- What does “detergent” mean in power washing
- Why water alone often fails
- The 6 detergent families and what each removes
- What “traffic film” and TFR mean
- What snow foam does (and what it does not do)
- How to choose a safe starting mix and patch test
- Simple safety rules like SDS, PPE, and runoff control
If you are new, start with what power washing is.
What power washing detergents are (and why water alone fails)
Power washing detergents are cleaning liquids that help water lift, break up, and rinse away dirt that plain water leaves behind.
A detergent is a mix of cleaners, often including surfactants (cleaning ingredients that help water spread and lift oily dirt). Surfactants matter because oil and water do not mix well on their own.
Soil type means what the dirt is made of, like grease, road film, fuel residue, or food fat. One detergent cannot work best on every soil type. When you match soil type to detergent family, you need less pressure and less scrubbing.
The 6 main detergent families used in power washing
Most power washing detergents fit into six families, and each family matches one common soil problem.
| Detergent family | Removes best | Common surfaces | Biggest caution |
| Alkaline degreasers | Oils, grease, heavy grime | Concrete, machinery, tiles, and some painted surfaces | Can stain soft metals or dull paint if too strong or left too long |
| Traffic Film Removers (TFR) | Road film mix on vehicles | Painted panels, lower vehicle sides, and industrial vehicles | Watch aluminium, dilution, and dwell time |
| Foaming agents (snow foam, foam boosters) | Loose dirt and film as a pre-wash | Vertical surfaces, vehicles, and cladding | Foam thickness is not the same as cleaning strength |
| Fuel cleaners (diesel and petrol residues) | Fuel residue and spill marks | Forecourts, spill zones, workshop floors | Runoff control and fire safety come first |
| Hydraulic oil cleaners | Sticky hydraulic oil on porous surfaces | Plant bays, forklifts, and concrete | Often needs repeat cycles on porous concrete |
| Food fat cleaners | Kitchen grease and solid fats | Kitchens, bin areas, exhaust zones | Slip risk and rinse discipline matter |
For a broader overview of product options, see pressure washing chemicals.
1. Alkaline degreasers
Alkaline degreasers are high-pH detergents that break oily grime into a rinseable mess so it can wash away.
What it is (plain language)
An alkaline degreaser is an alkaline cleaner (basic), meaning it has a higher pH (a number that shows how acidic or alkaline a liquid is). It works well on greasy soil because it helps oils loosen and lift from the surface.
Many alkaline degreasers also include surfactants that help water wet the surface. Better wetting means the cleaner reaches under the grime instead of beading up.
What it removes best (grease, oils, heavy grime)
Alkaline degreasers remove thick grease, oil films, and ground-in workshop grime best. They also help with soot and traffic grime on hard surfaces.
They work best when the grease is fresh or when you repeat the cycle on old buildup. Old grease can harden and need more dwell time, plus light brushing.
Where people use it (workshops, concrete, kitchens, machinery)
People use alkaline degreasers on workshop floors, machinery, and concrete pads. They also show up in kitchen cleaning because they cut cooking grease on tiles and washable walls.
In professional pressure washing work, we see alkaline degreasers do more work when people add light brushing on the worst spots. The water blast alone often leaves a thin, greasy film behind.
Key limits (surface compatibility and over-strength risks)
Alkaline degreasers can dull paint, etch soft metals, or stain bare aluminium if you use them too strongly or let them dwell too long. They can also dry into a sticky haze if you do not rinse fully.
Always start with the mildest mix that still works and do a small patch test. If a surface changes color or feels rough, stop and reassess.
Best-practice use (dwell time, agitation, rinse, do not let it dry)
Alkaline degreasers work best when you apply, wait, lightly scrub, and rinse before drying.
Use this simple flow:
- Wet the surface first if it is hot or very dry.
- Apply diluted degreaser evenly.
- Let it dwell (sit and work) for a short time.
- Use light agitation (gentle brushing) on heavy spots.
- Rinse well and do not let the detergent dry on the surface.
2. Traffic Film Removers (TFR)
Traffic Film Removers are detergents made to strip the thin, stubborn road film that clings to vehicles and equipment.
What does “traffic film” mean
Traffic film is the dirty film that builds up from road spray, exhaust soot, fine dust, oily mist, and bugs. It looks like a gray-brown haze, especially on lower panels and rear doors.
It sticks because it is a mix of oil-like soil and tiny particles. That mix often resists plain shampoo and water.
What TFR removes best (road film mix)
TFR removes the road film mix best, including traffic grime and bug residue. Many products describe it as a fast, “touchless” pre-wash style cleaner for fleet and heavy vehicles.
Some TFR products foam well, which helps them cling to vertical areas long enough to work.
Where TFR fits (fleet, trucks, lower panels, industrial vehicles)
TFR fits best on fleets, trucks, and industrial vehicles where road film builds fast. Operators often focus on lower panels, wheel arches, and the rear because that is where the film is thickest.
In professional pressure washing work, we see TFR succeed when people apply from the bottom up on vertical panels. This helps reduce streaks from running down.
Key limits (paint, aluminium, dilution, dwell time)
TFR can be too harsh on bare aluminium or delicate paint if it is too strong or left too long. Some guidance also warns that foam and dwell time still need control, even when the product “rinses easily.”
Treat dilution as a safety tool, not just a cost tool. Start mild, and increase strength only if needed.
Simple usage flow (apply, dwell, rinse)
TFR works best when you apply evenly, let it dwell briefly, and rinse fully.
A simple flow:
- Apply a diluted TFR with a sprayer or foamer.
- Let it dwell for a short, controlled time.
- Rinse well, especially around seams and trims.
3. Foaming agents (snow foam, foam boosters)
Foaming agents help detergents cling and spread evenly so they stay in contact with dirt longer.
What foam is for (cling and contact time)
Foam is mainly for cling and contact time, not for extra “power.” Foam keeps the detergent from sliding off fast, especially on vertical surfaces.
People also use foam to see coverage. Even coverage helps you avoid missed patches and over-spraying.
When foam helps most (vertical surfaces, pre-wash, even coverage)
Foam helps most on vertical walls, vehicle sides, and any area where a thin spray would run off too fast. It also helps as a pre-wash step to loosen film before you touch the surface.
Many how-to guides tell users to give foam enough dwell time, then rinse from top to bottom.
Foam myths (foam ≠ strength)
Foam thickness does not prove cleaning strength. A thick foam can still be mild, and a thin solution can still be strong.
Judge results by what lifts off after dwell and rinse, not by how “snowy” it looks.
Practical notes (dwell time, rinse, avoid drying)
Foam works best when you keep it wet and rinse before it dries.
In professional pressure washing work, we see dried foam leave streaks on glass and paint. A quick re-wet and rinse usually fixes it, but it wastes time.
4. Fuel cleaners (diesel and petrol residues)
Fuel cleaners target fuel residue and spill marks, which need extra safety steps before you start washing.
What it targets
Fuel cleaners target diesel and petrol residue, oily staining, and fuel odors near spill areas. They are not the same as general degreasers because fuel spills raise fire and runoff risks first.
You may also need absorbents and containment tools before any detergent step. This keeps fuel from spreading.
Where it is used (spill zones, workshops, forecourts)
Fuel cleaners show up in spill zones, workshops, loading areas, and fuel handling areas. These areas often have stained concrete and repeated drips.
Treat these jobs like spill response plus cleaning. Do not rush straight to pressure washing.
Key limits (runoff control, safety)
Fuel work needs runoff control because wash water can carry fuel into drains and soil. It also needs ignition control because vapors can ignite.
Follow local rules and site rules for disposal and separators when they apply. Planning where runoff goes is a core step in safe washing.
Basic safe approach (absorb first, then clean)
A safe approach is: stop the spread, absorb first, then clean what remains.
A simple flow:
- Block or protect drains before washing.
- Use absorbent material on the spill.
- Remove absorbed waste the right way.
- Apply a suitable cleaner to the stain that remains.
- Rinse with controlled runoff and collect wash water when required.
Read more about: Fuel Types for Hot Water Power Washers
5. Hydraulic oil cleaners
Hydraulic oil cleaners work best when they break a sticky oil film that has soaked into pores, then you repeat until the stain fades.
Why is hydraulic oil different (sticky, penetrates porous surfaces)
Hydraulic oil is sticky and often soaks into porous concrete, meaning it sits below the surface. Porous means the surface has tiny holes that hold liquid.
That is why one pass often leaves a shadow stain. You usually need multiple cycles.
Where it appears (plant equipment, forklifts, bays)
Hydraulic oil appears in plant equipment areas, forklift bays, service pads, and loading docks. These are also areas where runoff control matters because the wash water can carry oil.
It also appears near hoses, fittings, and parking spots where drips repeat.
Key limits (repeat staining, surface porosity)
Hydraulic stains can return because oil stays trapped in pores. Hot water can help, but it can also spread the oil if you do not contain the runoff.
Do not chase deep stains with high pressure alone. High pressure can drive oil deeper into cracks.
Practical approach (pre-treat, dwell, agitation, repeat if needed)
A practical approach is: pre-treat, dwell, scrub lightly, rinse, then repeat.
Start with:
- Pre-treat the stain with the right cleaner for oily soil.
- Let it dwell without drying.
- Brush the worst areas.
- Rinse and inspect while the surface is still wet.
6. Food fat cleaners (kitchen grease and solid fats)
Food fat cleaners remove cooking grease best when they prevent smearing and help you rinse the fat away instead of spreading it.
Why food fats behave differently (smear and re-deposit)
Food fats soften and smear when warmed, and they can re-stick as they cool. Re-deposit means the fat settles back onto the surface after you move it.
That is why “half rinses” leave a slippery film behind. Good rinsing matters as much as good chemistry.
Where it appears (kitchens, bin areas, exhaust zones)
Food fats build up in kitchens, bin areas, exhaust filter zones, and around grease storage. Floors and mats can hold thick fat that turns slick when wet.
These areas often need controlled hot water and careful runoff handling.
Key limits (slip risk, residue, rinse discipline)
Food fat cleaning has a high slip risk because fat plus water turns floors into ice. It also has a residual risk if you do not rinse fully.
In professional pressure washing work, we see most “grease smells” stay because people stop rinsing too soon. A longer rinse and better runoff control usually fixes it.
Practical approach (controlled heat if available, correct chemistry, rinse well)
A practical approach is: scrape first, apply the right cleaner, and rinse until the surface squeaks clean.
Use this flow:
- Remove thick solids first.
- Use controlled heat if available and safe for the surface.
- Apply the right cleaner for fats.
- Rinse very well and keep drains protected.
How to choose the right detergent
You choose the right detergent by matching the soil type and the surface, then start mild and prove it with a patch test.
Step 1: Identify soil (grease vs film vs spill vs fat)
Look at what the dirt is made of and where it came from. Grease from a kitchen behaves differently from road film on a truck.
If it wipes oily, think degreaser or oil cleaner. If it looks like a dull haze on paint, think TFR.
Step 2: Identify surface (paint, aluminium, sealed concrete, porous concrete)
Decide if the surface is delicate or porous. Paint and bare aluminium need gentler chemistry and tighter dwell time.
Porous concrete can trap oil, so it often needs repeated cycles. Sealed concrete usually rinses cleaner.
Step 3: Choose detergent family
Pick the family that matches the soil, not the brand name. Foam can be a delivery method, not a soil type.
If you are unsure, start with a general, mild cleaner and step up only if needed.
Step 4: Pick a safe starting dilution and do a patch test
Start with the label’s mild end of the mix range and test a small hidden area. Dilution means mixing the product with water to reduce its strength.
If the surface changes color, dulls, or feels rough, stop. Adjust product, dilution, or dwell time.
Step 5: Dwell, light agitation, rinse
Let the detergent dwell briefly, brush only where needed, and rinse before drying. This sequence beats “stronger mix and more pressure” most of the time.
Quick soil-to-detergent map
| Soil type | Best detergent family | Watch out |
| Thick grease on the floors | Alkaline degreaser | Can dull soft metals and paint if too strong |
| Road haze on paint | TFR | Do not let it dry, watch the aluminium |
| Loose dirt on the walls | Foam + mild detergent | Foam thickness does not equal strength |
| Fresh fuel spill residue | Fuel cleaner + absorb first | Runoff control and ignition risk |
| Sticky hydraulic stains | Hydraulic oil cleaner | Repeat cycles on porous concrete |
| Cooking fat buildup | Food fat cleaner | Slip risk, rinse until fully clean |
Application basics that affect results (without turning into a repair manual)
Great results come from good dwell time, correct dilution, even coverage, and a full rinse.
Dwell time is how long the detergent sits on the surface before rinsing. Many guides recommend giving foam a short dwell so it can work, then rinsing before it dries.
Dilution controls strength and safety. Use measuring tools and keep notes, especially when you switch surfaces.
Foam vs spray is mainly about coverage and cling. Foam helps on vertical panels, while a pump sprayer can target small oily spots.
Do not let the detergent dry because dried chemicals can streak, stain, or leave residue. If it starts to dry, re-wet lightly and rinse.
If you want a simple prep routine, use a power washer setup checklist. If heat is an option, compare hot water vs cold water power washing.
One more basic rule matters: flush your detergent system after use. Multiple pressure washer manuals say to run clean water through the injector system to clear chemicals from the line.
Safety, trust, and good practice
Safe detergent use starts with the SDS, basic PPE, and strict rules about mixing and runoff.
An SDS (Safety Data Sheet) is a standard safety document that explains hazards, safe handling, PPE, first aid, and storage. For the official section layout, see the Safety Data Sheet (SDS) section format.
Check the SDS before you use a new product because it tells you the main risks and the right controls. Safe Work guidance explains SDS as key safety information and says workplaces should keep copies for hazardous chemicals. Use these Safety Data Sheets (SDS) for a clear overview.
Default PPE is simple: wear gloves and eye protection unless the SDS clearly says you can do less. A NIOSH infosheet lists PPE like gloves and safety goggles, and warns workers not to mix bleach and ammonia products. See protecting workers who use cleaning chemicals.
Never mix chemicals, even if both seem “mild.” Mixing can release dangerous gases, and it can also make cleaners fail.
Plan runoff before you start because wash water can carry oils and detergents into drains.
Store chemicals sealed, labeled, and away from heat. If you want a simple university-style guide to SDS handling and review basics, use the Safety Data Sheets guideline (university guidance).
Disclaimer: Always follow the product label and SDS. Test a small area first.
Summary
Power washing detergents work best when you match the detergent family to the soil, protect the surface with mild dilution and patch testing, then control dwell time and rinse before drying.
Next steps:
- Identify the soil and surface using the decision map above.
- Pick the matching detergent family and start with a mild mix.
- Apply evenly, dwell briefly, brush only where needed, and rinse fully.
- Read the SDS, wear gloves and eye protection, never mix chemicals, and control runoff.
FAQs: Frequently Asked Questions
What is the safest detergent to start with for power washing?
A mild, general-purpose detergent has lower strength and a lower chance of surface damage, but it may not cut heavy grease fast. Use it first on painted surfaces, then step up only if soil remains. Always patch test and follow the SDS.
Can I use dish soap in a power washer?
Dish soap is a foaming detergent with high foam, but it can leave residue and may not work well through some injectors. It can also create too much foam for rinsing on large areas. Keep it off pump systems unless the manufacturer allows it, and flush with clean water after use.
What does TFR mean in pressure washing?
A TFR is a Traffic Film Remover with strong film-cutting ability, often used as a pre-wash on vehicles. Its key attribute is removing road film from lower panels and rear areas. The constraint is dwell time and aluminium sensitivity, so use mild dilution and rinse before it dries.
Is TFR safe on aluminium?
A TFR often has an alkaline cleaning action that can stain bare aluminium if it is too strong. Its compatibility depends on dilution, temperature, and contact time. The constraint is to patch test and keep dwell short, then rinse fully.
Does thicker snow foam clean better?
Snow foam has the attribute of cling and even coverage, not automatic extra cleaning power. Thick foam can still be mild because foam’s look does not equal chemical strength. The constraint is to judge by results after dwell and rinse, and never let the foam dry.
How long should detergent dwell before rinsing?
Dwell time is the working time that lets surfactants lift soil from the surface. The right dwell depends on heat, wind, and soil level, so keep it short and controlled. The constraint is to rinse before drying to avoid streaks and residue.
What detergent works best for oily concrete?
An alkaline degreaser has the attribute of breaking oily soil into a rinseable mess. It works best on concrete and machinery areas, but it can still leave a shadow on porous slabs. The constraint is to use light brushing and repeat cycles instead of going stronger and longer.
How do I clean a fuel spill area before pressure washing?
Fuel residue needs a cleaner made for fuel soils, plus spill control tools. Its key attribute is risk, since fuel can spread in runoff and may ignite. The constraint is to absorb first, protect drains, then clean what remains, and control wash water.
Why does the hydraulic oil stain keep coming back?
Hydraulic oil has the attribute of deep soaking into porous concrete. That trapped oil can wick back to the surface after rinsing. The constraint is to pre-treat, dwell, agitate, and repeat while controlling runoff around drains.
Do I need to flush my detergent injector after use?
A detergent injector has the attribute of pulling a chemical through a line at low pressure. If you leave detergent in the line, it can clog parts and leave residue in the system. The constraint is to flush with clean water after use, as many manuals instruct.