I don't think so and my sows have eaten quite a lot of plastic so far...
Moreover, the plastic house cannot be eaten so easily; they can nibble some little part... but the plastic is hard.
I had (and still have) some problem with a tunnel made of a plastic net. It is their favourite tunnel, they have grown inside it and I cannot throw it away although it has now a large fire exit and a lot of piece are missing!
this is how it looked like last March
also their plastic box used as a house has some hole...
They can have a good old chew on them but I don't think they actually eat it.
The only thing I'd say about plastic igloos is be very careful with their usage in this hot summer weather. I prefer to use cardboard boxes this time of year as it's somewhere they can be in the cool. Plastic heats up and becomes a bit of an oven if in direct sunlight.