Do I need to contact the emergency vet or take him there now?

At about 4:30 this morning (currently 6:30) my 56 pound dog at a Ice Breakers Frost mint which contains Xylitol. I know that Xylitol is poisonous to dogs if ingested and can cause liver damage and even death. The mints are my husbands and I had repeatedly told him that the mints he buys on a daily basis are toxic to dogs because they contain Xylitol. I asked him if he insists on buying these to be careful with them and keep them put up and don't even keep them in his pants pockets. This morning right after the alarm went off I heard something click on the floor because we have hard wood floors but I was still laying in bed. The cat was batting something around and playing because I could hear it. The dog got up to go see what it was and by that time I was getting up and he came in chomping on something. When I walked in the front room I noticed a handful of mints on the shelf and the Ice Breakers Frost container was laying next to them. I asked my husband why there were up there and he said because the mints had been in his pocket and he just put them up there. I told him these were the poisonous ones and Milo had eaten one and he told me to shut the f up and stop running my mouth. I left the house a little over an hour after he had eaten it and he seemed fine-he was wanting to play and was wagging his tail. I read things saying the effects could take place in as little as 30 minutes. His regular vet doesn't open for several hours. Do I need to be calling the emergency vet or taking him there right now?