Question: do toiletries have to be in a plastic bag?
Answer: Liquids and gels must be in individual containers of 3.4 ounces (100 milliliters) or less and placed inside one clear, quart-size, plastic, zip-top bag (such as this option from Ziploc). The TSA emphasizes that containers should fit comfortably into your bag and that only one bag is permitted per passenger.