Eugenol is a naturally-occurring component of both cinnamon and cloves. It is extracted from their essential oils and widely used in mouthwash, medicines, flavourings and fragrances. Eugenol is also one of the 26 potential allergens outlined by the 7th Amendment to the Cosmetics Directive. Having it specifically listed is extremely fortunate for soapers – not because it is a particularly dangerous component, but rather because it causes soap to seize.
To help European soapers comply with Amendment 7, we will supply both the MSDS and the allergen declaration for every fragrance oil we sell. The allergen document will reveal the presence of eugenol if it is contained in the oil. Most likely, it will only be found in floral fragrances, as that is the only type of fragrance that seems to require eugenol out of necessity, hence the tendency of most florals to accelerate or seize up once added to the soap pot.