Puppy Ate Lid Of Eyeliner?

You know how eyeliner has that plastic lid? Well my 5 month old dog got a hold of it and ran under the bed, I was home alone and it was truly impossible to catch him and take it out of his mouth. I could hear him chewing it, I dont know if he ate the whole thing. I just wanna know if it's life threatening or if he'll just pooop it out? I don't think a vet check up is nessacary it's not open today anyway, any advice is appreciated? How long until it'll pass?