Protect your eyes from alkalis: What you need to know!

Why are concrete/cement/plaster products in the eye such an emergency? 

Most cement, lime, mortar, concrete, and plaster products are hazardous substances that contain strong alkalis.

As seen in the image above, alkalis are on the opposite end of the PH scale from acids, however, can be equally as dangerous, being extremely destructive to your eyes. The way you handle the first seconds, minutes, and hours after you get the dry powder or wet mix in your eyes, will determine the outcome. 

Alkalis may start their damaging work in your eye without much pain or symptoms, but over time the damage gets worse. So beware, follow the first aid steps below even if you don’t feel pain. 

Don’t become one of the statistics: in 2021, there were 56 burn injury claims to the eyes in the NZ construction sector, with 90% of chemical eye burn injuries that could have been prevented.

What is the First Aid treatment if I get concrete/cement products in my eye?

Every second counts! Run to the closest tap, eye wash station or water bottle and start flushing your eye. You are aiming to dilute the alkali to lessen the damage.

Wash your face and hands, you don’t want to get more cement product in your eyes. Flush your eye with a steady stream of running water. Let it pour into your eye while lifting both eyelids to rinse out all the cement granules underneath. Do not reuse the water and do not let contaminated water run into the unaffected eye.

  • Do not rub your eye. 
  • Remove contact lenses as soon as possible.
  • Continue flushing while you or someone else calls 111, or the NZ National Poisons Centre: 0800POISON (0800 764 766) for instructions. Have your concrete/cement/plaster Safety Data Sheet (SDS file) handy, as the medical services will base their instructions on the product information in the SDS file (for instance, the higher the pH of the product, the longer you need to flush the eye).
  • You must see a doctor urgently when an alkali has entered your eye. Continue flushing the eye en route to the medical centre. The doctor will continue flushing your eye until its pH is back to normal. Take the SDS file along with you.

What will happen if I do not flush my eye, or stop too early?

If you do not flush your eye, or stop before you are told to do so, you may suffer from permanent eye damage, dry eyes, vision loss and more. 

How can I protect my eyes?

  • Training: everyone on-site should know about the risk, prevention, and First Aid treatment of cement/concrete/plaster products in the eye.

  • Do not touch your eyes when working with chemicals, wear strong gloves whilst handling material, and remove and wash hands before eating, nitrile or chemical-resistant gloves are best

  • Wear sealed safety goggles to protect against dry cement/concrete/plaster dust, for instance when mixing, and when the risk of wet splashing is high. Wear safety glasses when the risk of wet splashing is low.


  • Have an eye rinse station at hand and know the location of the nearest tap.



  • Keep your product SDS files, available from your product suppliers, on-site. For more information on SDS files, click here.


HazardCo’s Site Box or Emergency Box is ideal for storing your SDS files and eye wash stations on-site. You can also upload and store your SDS and other H&S documents on the HazardCo Hub to keep them all in one place.

If you have an incident where someone gets cement/concrete in their eye, remember to report this as an incident in the HazardCo App. This will automatically be added to your incident register in the HazardCo Hub, and the Advisory team will be in touch with you to discuss next steps if it is deemed to be notifiable to WorkSafe NZ.

For questions or support, contact the friendly advisory team at HazardCo at 0800 555 3339 or