Merchant
NY
Sometimes if using a natural or essential oil when used in many plastic containers like HDPE for example there can be a compatibility issue that happens and a product will go rancid and smell bad. Certain preservatives can be added to stabilize a formula with essential oils in it and it can still be in a plastic container. Glass is best when using essential oils and certain types of PET plastics are a safer container than HDPE is. Example MDC uses a excellent PETG plastic container. Could be a whole other problem though so just another possibility I thought I'd add.