What is Polyglaze Windscreen Additive, and where should you use it?

Polyglaze Windscreen Additive is a cleaning concentrate which is added to the windscreen washer reservoir. Its purpose is that it allows the windscreen to be cleaned effectively while driving — it works through the washer jets and wipers, not by hand.

It is supplied in 500mL bottles and is suitable for use in all vehicles. Beyond cleaning, it is formulated to reduce smears and streaking for enhanced visibility, to clean and lubricate the wipers to increase their working life, and to help prevent glare.

One instruction is flagged as important on the data sheet and is worth knowing before you open the bottle: immediately clean up any spills of the concentrate, as staining will occur.

Technical specification

Property	Typical result
Appearance	Clear blue liquid
Specific gravity	0.992 – 1.00
pH	6.5 – 8.5
Pack size	500mL bottle
Dose — standard reservoir	75mL of concentrate
Dose — reservoirs over 4 litres	Approximately 150mL
Shipping / dangerous goods	Not restricted

These figures are indicative data from the product's technical data sheet and are not intended for the preparation of specifications.

What the dosing figures mean for you

The dose is specified per reservoir rather than per litre, with a step at the 4 litre mark: 75mL normally, and approximately 150mL for reservoirs over 4 litres. The practical reading is that a 500mL bottle covers about six to seven standard reservoir fills, or about three on a larger vehicle.

It is also worth noting how the topping-up works. You add the concentrate once, then top up as required with clean water — you do not re-dose every time the level drops. That is why using the stated amount at the start matters: it is what the whole reservoir's worth of washing is being mixed to.

The pH of 6.5 to 8.5 sits either side of neutral, and the specific gravity of 0.992 to 1.00 is around that of water. This is a thin, near-neutral concentrate rather than an aggressive cleaner, which is consistent with a product that will be sprayed repeatedly onto glass and rubber and left to run down the paintwork below.

Why "cleans and lubricates wipers" is more useful than it sounds

Most wiper blades do not fail because the rubber wears out — they fail because grit and road film accumulate on the blade edge, and that contaminated edge then chatters and smears instead of clearing the glass. A washer additive that cleans and lubricates the blade is treating that cause, which is why the stated benefit is an increase in the wipers' working life rather than just a better wipe today.

The glare claim works the same way. Glare from a windscreen is mostly caused by the film of road grime and smeared residue scattering light — worst into low sun and against oncoming headlights at night. Keeping the screen genuinely clean is what reduces it.

Where to use it

In the windscreen washer fluid reservoir of all vehicles. This is not a hand-applied glass cleaner — for cleaning glass by hand, Polyglaze Glass Cleaner is the product in the same range for that job.

How to use it

1. Add 75mL of concentrate to your vehicle's windscreen fluid reservoir.
2. For vehicle reservoirs over 4 litres, add approximately 150mL.
3. Top up as required with clean water.
4. Clean up any spills of the concentrate immediately — staining will occur if you leave them.

Step 4 deserves attention because of where the reservoir filler usually is: in the engine bay, above and beside painted panels and plastic covers. Keep a rag with you when you pour, and wipe any run-down straight away rather than at the end of the job.

Safety and storage

• Selleys notes it is safe practice for all users to wear gloves when handling strong cleaners.
• Wash undiluted product off skin with plenty of water.
• If eye contact occurs, hold the eyes open and flood with water for 15 minutes. Seek medical attention if irritation persists.
• Keep out of reach of children.

For storage, protect the product from freezing, store the container out of sunlight, and keep it tightly closed. It is classified as not restricted for shipping and dangerous goods purposes.

Hazard classification

Classified as hazardous under Safe Work Australia GHS 7, with the signal word Warning.

• Skin corrosion/irritation — Category 2. H315: causes skin irritation.
• Eye damage/irritation — Category 2A. H319: causes serious eye irritation.

Not classified as Dangerous Goods by the criteria of the Australian Code for the Transport of Dangerous Goods by Road & Rail or the New Zealand NZS5433 — the "not restricted" line in the specification above. A product can be unrestricted for transport and still classified as hazardous for handling; the two are answering different questions.

What is in it

Chemical entity	CAS number	Proportion (w/w)
Ethylene glycol mono butyl ether	111-76-2	1–10%
Ethanolamine	141-43-5	<1%
Glycine, N-methyl-N-(1-oxododecyl)-, sodium salt	137-16-6	<1%
Ingredients determined to be non-hazardous or below reporting limits	—	Balance

The classification describes the concentrate in the bottle, which is the only form of this product you ever touch. Once 75mL has gone into a four-litre reservoir it is diluted more than fifty-fold and then topped up with water from there. All of the exposure in this job happens in the ten seconds you are pouring, in an engine bay, often at an awkward angle — which is the case for putting the gloves on before you unscrew the cap rather than after.

The component that gives the product its cleaning power is the glycol ether. It is the solvent that lifts the oily road film a plain detergent leaves behind, which is what a washer additive is bought for, and at 1–10% it is the largest declared ingredient. It is worth noticing that the skin first-aid direction on this safety data sheet is stronger than on most of the range: flush for 15 minutes and then get to a doctor, rather than flush and watch. Solvents of this class are the chemistry usually behind a direction that firm — they are absorbed through skin rather than merely sitting on it — although the safety data sheet does not attribute the classification to any one component, so read that as the likely explanation rather than a sourced fact.

This also puts a second reason behind the page's instruction to clean up spills of the concentrate immediately. That instruction is given above because the product stains. The safety data sheet gives you the other half: the thing you are wiping up is a skin irritant, so wipe it with a rag rather than a bare hand, and wash your hands afterwards.

One last point about the bottle itself. It is a clear blue liquid, at about the density of water, sold in a 500mL bottle that lives in a garage or a boot. Keeping it out of reach of children is a direction on the safety data sheet, not just good practice, and it is worth following for a product that looks exactly like a soft drink.

Protection

• Eye protection — safety glasses while pouring.
• Gloves — nitrile rubber is suitable for intermittent contact. Glove construction and conditions vary, so make your own final assessment.
• Clothing — overalls and closed footwear. The SDS lists safety shoes.
• Ventilation — handle in a well-ventilated area. In practice, an open bonnet outdoors.
• Wash contaminated clothing and protective equipment before storing or reusing it.
• Storage — cool, dry and well ventilated, out of direct sunlight, away from sources of heat and ignition, tightly closed, protected from freezing, checked for leaks, and out of reach of children.

First aid

Exposure	What to do
Eyes	Hold the eyelids apart and flush the eyes continuously with running water. Continue until advised to stop by the Poisons Information Centre or a doctor, or for at least 15 minutes, then get to a doctor or hospital.
Skin	Immediately remove contaminated clothing and flush the skin and hair with running water. Continue flushing until advised to stop by the Poisons Information Centre or a doctor, or for 15 minutes, then get to a doctor or hospital.
Inhalation	Remove the person from exposure without becoming a casualty yourself. Remove contaminated clothing and loosen the rest. Let them take the most comfortable position, keep them warm and at rest until fully recovered. Seek medical advice if effects persist.
Swallowed	Rinse the mouth with water. Do not induce vomiting. Give a glass of water to drink. Never give anything by mouth to an unconscious person. If vomiting occurs, give further water. Seek medical advice.

If poisoning occurs, contact a doctor or the Poisons Information Centre — 131 126 in Australia, 0800 764 766 in New Zealand — with the container to hand. Selleys emergency line: 1800 220 770 in Australia, 0800 220 770 in New Zealand.

Common questions about Polyglaze Windscreen Additive

How much do I add?

75mL of concentrate to the reservoir. For reservoirs over 4 litres, approximately 150mL.

Do I dilute it before pouring it in?

No. Add the concentrate to the reservoir, then top up as required with clean water.

How many doses do I get from a bottle?

The bottle is 500mL, so at 75mL per dose that is around six to seven standard reservoir fills, or about three at the 150mL rate for larger reservoirs.

Do I need to add more every time I top up with water?

The directions say to top up as required with clean water. The dose is specified per reservoir fill of concentrate, not per top-up.

Will it stop my wipers smearing?

It is formulated to reduce smears and streaking, and to clean and lubricate the wipers, which is what increases their working life.

Can I use it in any car?

It is stated as suitable for use in all vehicles.

What happens if I spill some in the engine bay?

Clean it up immediately. The data sheet flags this as important — staining will occur if concentrate is left on a surface.

Is it an antifreeze for the washer system?

No such claim is made. The only temperature instruction given is a storage one: protect the product from freezing.

Can I use it as a hand-applied glass cleaner?

It is specified as a concentrate for the washer reservoir. For cleaning glass by hand, use Polyglaze Glass Cleaner.

Do I need gloves?

Selleys notes it is safe practice for all users to wear gloves when handling strong cleaners.

How should I store the bottle?

Protect it from freezing, keep it out of sunlight and keep it tightly closed.

Is it part of a kit?

Yes — it is one of the products in the Polyglaze Exterior Car Care Kit, along with Wash & Wax, Wheel Cleaner and a sponge.