Australians use a lot of lauryl sulfates. According to the Australian Industrial Chemicals Introduction Scheme (AICIS), the combined use of sodium lauryl sulfate and ammonium dodecyl sulfate in Australia, as previously reported under NICNAS, sits in the range of 1000–2000 tonnes a year, mostly in cleaning, personal care and cosmetic products (AICIS evaluation statement, December 2022).
One of those uses is our cup cleanser. Lunette Cup Wash contains ammonium lauryl sulfate, and this guide explains what that ingredient is, how it compares with sodium lauryl sulfate, and what the rest of the label means for your period cup.
Quick answer: Ammonium lauryl sulfate (ALS) is the cleansing surfactant in Lunette Cup Wash, alongside cocamidopropyl betaine and lemon and eucalyptus oils. AICIS lists it as valued for foaming, cleansing and rinsing. A US safety review found ALS appears safe in brief-use products that are thoroughly rinsed off, which is how a cup wash is used.
What is ammonium lauryl sulfate?
Ammonium lauryl sulfate is the cosmetic (INCI) name for ammonium dodecyl sulfate, CAS number 2235-54-3. AICIS describes this family as a straight 12-carbon chain ending in a sulfate group, neutralised by an ammonium, sodium, potassium or magnesium ion, and used as anionic surfactants. Its molecular weight is 283.43 g/mol.
All the lauryl sulfates in the AICIS group are listed on the European Commission's CosIng database as cleansing surfactants.
Is ALS the same as SLS?
No, but they are close cousins. Sodium lauryl sulfate (SLS) uses sodium as its partner ion; ALS uses ammonium. AICIS groups them in the same evaluation because they share the same structure and uses. A 1983 US expert assessment, held in the US EPA's HERO science database, also reviewed sodium and ammonium lauryl sulfate together and reached the same safety conclusion for both.
Does ammonium lauryl sulfate irritate skin?
It can, depending on strength and contact time. The 1983 US assessment found irritation increased directly with concentration, closed patches irritated more than open ones, and rinsing reduced irritation from ALS solutions. It concluded both lauryl sulfates appear safe for discontinuous, brief use followed by thorough rinsing, and recommended that leave-on products keep concentrations at or below 1%.
A cup wash is a rinse-off product used on silicone with water, and its label says it is not for intimate areas.
Is it bad for the environment?
AICIS concluded that dodecyl sulfate salts are not persistent, have low bioaccumulation potential and, at Australian use levels, are unlikely to pose a significant risk to the environment. It also reports that SLS is readily biodegradable in standard tests, with 94–97% degradation measured.
What's on the Lunette Cup Wash label?
The 100 ml cup cleanser lists these ingredients:
- Aqua
- Ammonium Lauryl Sulfate
- Cocamidopropyl Betaine
- Citrus Limonum (Lemon) Peel Oil
- Eucalyptus Globulus Leaf Oil
- Sodium Benzoate, Potassium Sorbate, Sodium Chloride, Citric Acid
- Parfum, Linalool, Citral, Limonene
It is vegan and pH balanced, scented with lemon and eucalyptus oil, and needs water to use. Warnings on pack: for period cups only, not for intimate areas.
To use it, rinse your period cup in cold water each time you empty it, then wash it with warm water and Cup Wash or a mild, unscented soap. Boil 5 minutes before first use and after each completed cycle.
Frequently asked questions
Why does Lunette use ammonium lauryl sulfate?
Lauryl sulfates are widely used because, as AICIS puts it, they combine favourable foaming, cleansing and rinsing properties with relatively high water solubility. In Cup Wash, ALS sits second on the ingredient list after water, with cocamidopropyl betaine and lemon and eucalyptus oils. The product is formulated for cleaning period cups only.
Is ammonium lauryl sulfate dangerous?
Not in rinse-off use, according to a 1983 US expert safety assessment, which found ALS and SLS appear safe in brief-use products followed by thorough rinsing. Irritation increased with concentration and longer contact, so it suits wash-off products like a cup cleanser rather than leave-on skin care.
Can I use Cup Wash when I'm away from a sink?
No, Cup Wash needs water. If you are travelling or using a public toilet without a sink, wipe your menstrual cup with a Lunette Cup Wipe and wash it under running water once you are back home. The 100 ml tube is TSA friendly for carry-on bags.
What soap can I use on my period cup?
Lunette's cleaning guide suggests Lunette Cup Wash or a mild, unscented soap with warm water each time you empty the cup. Skip the dishwasher altogether. Between cycles, boil the cup, let it air-dry and store it in its linen pouch so it is ready for your next period.
See also: how to clean your menstrual cup and cleaning your Lunette cup in a public toilet.
A well-kept cup goes the distance. The Lunette period cup is made in Finland from 100% medical-grade silicone and lasts up to 10 years with proper care. Look after it with Lunette Cup Wash and our cleaning guide.
This information is general in nature and is not medical or dermatological advice. Speak with your GP or pharmacist if you have sensitive skin or known allergies.
