no seal on this. not even a 3rd full, the powder was all over the container and in the paper amazon bag. not sure if i actually got the 300g or not. this product should be sealed. the sulphur was all over my hands from pulling it out of the bag. there is a warning lable on it that says not to get it on your skin or breath it in but i don't know how you can avoid this if it comes unsealed. i should have read the reviews before i bought it