It is not dangerous for a person to swallow their daily use of toothpaste in small amounts. Still, if they accidentally ingest more, yes, that can cause adverse side effects such as nausea and vomiting, depending on how much was swallowed. In some cases, though, fluoride found in toothpaste may cause acne breakouts in some people, especially those with a history of acne or oily skin. However, the amount found in toothpaste is not enough to affect sebaceous glands, which are mainly affected by fluoride ions present when drinking fluoridated water, so try to drink bottled or filtered water if you have concerns about this issue.