United Kingdom allows the use of Natamycin on certain products. You can apply natamycin in the external surface of clotted cream in United Kingdom when you do not exceed 10 µg/g. It doesn’t have bacterial action so it can be applied in food industry. Room temperature does not affect the properties of natamycina.
The laws in United Kingdom for this substance is subject to change. It is important to check the laws of each country.