Keeping antifreeze out of our seas

There’s one yearly ritual that we may have overlooked that is actually polluting our waters in a big way: it’s the opening season’s first trip and turning on our engines full of antifreeze…

Getting our boats back in the water for a wonderful season of sailing – there is nothing like the feeling! We hop on, warm up the engine, slip the lines and off we go. Except we may have just dumped 2-3 litres of antifreeze into our ocean.

Who uses antifreeze?

Anywhere that winter temperatures are likely to reach below zero Celsius, many of us sailors store our boats with some antifreeze in the engine. To prevent the engine’s cooling system from freezing over and bursting ducts, pouring some of that brightly coloured liquid in and closing the valves helps to preserve our engine systems over the cold months. And then, on that first spring day, we open them up again, replacing the antifreeze with external water to cool our engine, pushing all of the engine antifreeze into the sea.

Now, most manufacturers say that their antifreeze doesn’t harm the environment and that propylene glycol, its official name, is biodegradable. But if it didn’t come from the ocean, we shouldn’t be putting it in the ocean. As an example, antifreeze prevents water from freezing…

But really, what do the number show?

If we look at the numbers, we see that this is not an issue to be taken lightly – estimates say that in the Netherlands alone, recreational boating is responsible for dumping about 500.000 litres of antifreeze into surface waters every spring. This equals 15 shipping containers of antifreeze!

How to dispose of your antifreeze properly
(a successful experiment)

So, our crew tried something new with a boat engine for the first time – we tried to catch it in a bucket. Here’s some of the things we found :

(Two people are recommended for this job)
We tied a bucket under the engine’s exhaust. I used two pieces of line in a v-shape to prevent the bucket from going all over the place in the wind.
We started the engine so we could make sure the bucket would be in the right place when the antifreeze would start spilling out – two people are recommended for this job.

LOADS of foam that started filling the bucket. Apparently, the antifreeze gets diluted with cooling water and it takes more than a 10 litre bucket to completely rinse the cooling system clean, so have a second bucket ready!

Make sure you use your marina’s chemical waste bin or bunded drainage system to dispose of the antifreeze

Does your marina not have chemical or
hazardous waste disposal?

How clean is your marina?

Antifreeze is a necessity at high latitudes and it is possible to ensure we keep it out of the sea. With a bit of practice and some preparation, it only takes an extra 15 minutes per boat to collect engine water for the first time in Spring, AND, we all get karma points for helping keep our ocean clean.
We depend on clean and healthy oceans, so let’s be Clean Sailors.

Sailors, what do you think?

What do you think of antifreeze manufacturers’ claim that there’s no harm in dumping antifreeze into the water?
We have heard of completely organic products like Vake. We’d like to hear your experiences with these kinds of products.
Have you tried to catch your antifreeze in a bucket and do you have tips?
Does your marina have a facility to get rid of your antifreeze? If not please drop us a line, we may be able to help through our Cleaner Marina project!