Sometimes, (rarely) the packages of oil delivered are put in a mailbox in direct sunlight and the product could heat up. I have accidentally left the oil out in direct sunlight and the Miron Glass definitely attracts the heat from the sun. I was still able to use the oil as per normal. The products are also packaged in light brown boxes with lots of packing materials so it never exceeds temperatures that will damage the product with normal shipping logistics.
All of our Oils are carefully safety sealed to ensure purity. It is the black adhesive tab that goes between the cap and the bottle. When you twist the cap off, the small safety seal tears off so you know it is the first time the product has been opened. Any unsealed products you can return for either a refund or replacement.