YES! Since dry ice is solid Carbon Dioxide once it sublimates it can be poisonous and cause suffocation! Always handle dry ice in a well-ventilated area while wearing the proper gear. If dry ice has been in a confined space (e.g., a closed car or room) for more than 10 minutes, open the doors and windows before entering or you may experience difficulty breathing. Leave the area immediately if you start to breathe quickly or have any difficulty breathing. You never want to keep dry ice in a glass or tightly-sealed container. As the dry ice starts to sublimate into gas it will cause the air-tight container to expand and possibly explode. KEEP AWAY FROM CHILDREN!