What is the coating on my foundation wall?

[Nooblet]

Hi, I was down today changing the wastewater pump and tidying up the crawl space and noticed there is a coating painted/sprayed on the foundation wall. It neither feels nor looks like paint. Easy to break off, only a few millimeters thin. Murky transparent, somewhat whitish. Does anyone know what this might be? Attaching a picture I found that I took down in the crawl space at another time, zoom in, and you'll see it.

 

[Manganbangan]

Don't mean to be rude but it's a horribly bad picture to see anything. If it sparkles and looks like cotton candy, it's salt efflorescence.

 

[Nooblet]

Don't mean to be rude but it's an awfully bad picture to see anything on. If it's sparkling and looks like cotton candy, it's salt efflorescence.

Yes, the picture is one I took on a different occasion. I can go down and take a better picture tomorrow. I'm doubtful about salt efflorescence, this feels more like some sort of surface treatment.

 

[Manganbangan]

It looks like a layer of plaster that has come loose here and there.