As any parent who has ever walked through their house in bare feet knows, LEGO bricks are among the most resilient objects on the planet. Able to withstand years of manipulation and abuse, the sets remain intact even when doll heads, action figure limbs, and electronic games fall by the wayside.

If you needed further confirmation on their durability, science is here to help. New research from the University of Plymouth in the UK published in the journal Environmental Pollution demonstrates that the bricks could survive in some form for as long as 1300 years in the ocean. Not even constant exposure to saltwater can stop them.

This projection was determined by researchers collecting LEGO bricks that had washed ashore in Southwest England. They compared the mass of these found bricks to similar LEGOs taken from storage. The 50 pieces, which are made of acrylonitrile butadiene styrene (ABS) plastic, were retrieved from outdoor saltwater exposure to be washed, weighed, and measured. Their approximate age was estimated by using an X-ray fluorescence spectrometer to see which chemical elements were missing. A rate of deterioration was made based on their condition relative to the stored bricks.

The result? LEGO bricks could hold on to some semblance of shape for anywhere between 100 to 1300 years. While not necessarily usable—some of the pieces decayed into blobs of plastic—researchers were able to demonstrate that microplastics can endure in the environment for indefinite periods.

“The pieces we tested had smoothed and discolored, with some of the structures having fractured and fragmented, suggested that as well as pieces remaining intact they might also break down into microplastics,” Andrew Turner, the lead author and associate professor of environmental sciences at the University of Plymouth, said in a statement. “It once again emphasizes the importance of people disposing of used items properly to ensure they do not pose potential problems for the environment.”

[h/t Geek.com]