Grapefruit oil
Under the IFRA Standards a rinse-off soap may hold up to 50 % of this oil, a limit set by its 2-Hexenal.
IFRA maximum for soap
Restricted constituents, at the typical levels IFRA's annex gives:
- Citral
- 0.1 %
- Citronellal
- 0.1 %
- Citronellal
- 0.1 %
- Geranial
- 0.06 %
- Neral
- 0.04 %
- 2-Hexenal
- 0.03 %
Worked out from typical levels. A supplier's certificate for your lot comes first, and its figure is the one to follow.
Check a blend against its IFRA limits and list its allergens in the fragrance and allergen calculator.
How essential oils behave in soap, and how much to use: Scenting soap.
Identity and labelling
Citrus Paradisi Peel Oil
- Botanical name
- Citrus × paradisi
- CAS
- 8016-20-4
The EU does not name this oil itself as an allergen to label, but some of its constituents may be: the fragrance allergen tool works them out for a recipe.
What it is and how it behaves in soap
Grapefruit oil is pressed from the peel of the grapefruit, Citrus × paradisi, and smells bright, bittersweet and juicy, drier than orange.
Like other peel oils it fades from cold process soap. Grosso uses grapefruit to brighten blends and to fill out other citrus; to make it last, anchor it as Faiola anchors lime, with a sturdier citrus scent such as litsea or lemongrass, and add a base note (Fisher). Cable uses it at 1.5 % of the oils beside geranium. The IFRA figure on this page is the ceiling.
Pressed grapefruit oil is phototoxic, so IFRA restricts it in leave-on products, though not in rinse-off soap. Citrus oils go off within months (Cavitch), and oxidised limonene is a potent skin sensitiser (SCCS), so buy a little at a time and keep it cold.
Sources
- CosIng, the cosmetic ingredient database: CITRUS PARADISI PEEL OIL, European Commission
- Alicia Grosso, The Everything Soapmaking Book, 3rd edition, Adams Media (2013). Grapefruit brightens blends and fills out other citrus
- Anne-Marie Faiola, Pure Soapmaking, Storey Publishing (2016). Volatile citrus anchored with a sturdier scent of a similar nature, such as lemongrass with lime
- David Fisher, The Complete Photo Guide to Soap Making, Creative Publishing International (2018). Base notes such as patchouli and cedarwood give blends staying power
- Kelly Cable, The Natural Soap Making Book for Beginners, Althea Press (2017). Grapefruit at 1.5 % of the oils with geranium
- IFRA Standard: Grapefruit oil expressed (Amendment 49), International Fragrance Association (2020). Restricted for phototoxicity in leave-on categories; no restriction in category 9
- Susan Miller Cavitch, The Natural Soap Book, Storey Publishing (1995). Citrus oils are vulnerable after about six months
- Opinion on fragrance allergens in cosmetic products (SCCS/1459/11), Scientific Committee on Consumer Safety, European Commission (2012). Oxidised limonene is a potent sensitiser