A Melbourne makeup artist has sparked debate over Lucas Papaw Ointment's ingredients.

It’s hard to think of a more “cult” Aussie product than Lucas’ Papaw Ointment.

The salve in the ubiquitous red tube has burrowed its way into thousands of handbags and bathrooms around the nation, and in recent years it’s hit cult status — stars like Rose Byrne, Cate Blanchett, Rosie Huntington-Whiteley, Alexa Chung and Natalie Portman have sung its praises.

The ointment is used as a lip balm, nappy rash salve, insect bite relief and everything in between, and it’s a total steal at roughly $5 a piece. So what’s not to love?

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Well, if you ask Melbourne-based makeup artist Wanda Waller, there’s one big issue with this beloved paw paw creation: its namesake fruit makes up just four per cent of the formula, with the rest comprising petroleum jelly.

In a Facebook post that has attracted almost 20,000 shares, Waller says she refuses to use Lucas’ Papaw Ointment because its concentration of petroleum jelly — also known as petrolatum, mineral oil, liquid paraffin or paraffin oil — is potentially harmful to the skin.

“[It] is a by-product of the oil industry, coming from crude oil that has been refined and heavily processed. It is the cheapest way you can make a moisturiser, one that feels amazing on the skin but is actually not that good for you,” she writes.

“Petroleum jelly creates a physical barrier against the skin, meaning moisture can’t get in or out. It only reduces moisture loss which is why it feels like it is moisturising. It can clog the pores, slowing the skin’s ability to eliminate toxins.” (Post continues after gallery.)

Ultimately, Waller claims, the ointment is “basically a repackaged more expensive version of Vaseline.”

Those are fighting words right there.

Although tubes of Lucas’ Papaw Ointment clearly state the product contains 39 mg/g of fermented paw paw, Waller’s observations have prompted some surprised, emotional responses from devout fans.

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“Devastated but thank you for the info,” one wrote. “What??? Oh God – who knew – thanks for sharing,” said another.

A response to Waller’s claims has been posted on the Lucas Papaw Remedies website. It states the petroleum jelly used as a base for the popular product is pharmaceutical grade, and that the negative effects apply to lower quality, “lesser purified” versions.

"Lucas’ Papaw Ointment contains high quality pharmaceutical grade petroleum jelly as the carrier for the active ingredient – Fresh fermented papaw. Petroleum jelly does not block pores, is not carcinogenic or toxic. It is certified to comply with international and Australian safety standards," the company writes.

"Petroleum jelly by itself aids healing because it seals out germs and moisture to protect wounds while the body gets on with repairing itself. Then with the added bonus of papaw, which is a natural antiseptic and has natural drawing properties that clean wounds, it has shown to be a very effective healing agent."

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They also link to a scientific study that indicates petroleum jelly doesn't block the pores of the skin, as is commonly claimed.

"We wanted to put this information out to you, our valued customers, and let you know that our product is safe, it is effective, it is approved by the Therapeutic Goods Administration (TGA), it is made from Australian grown papaws, and all other ingredients are sourced from the highest quality accredited suppliers, and our product is made wholly in Australia," General Manager Lynette Swinglehurst has added in an updated statement.

Several commenters on Waller's post have shared links to similar products with higher paw paw concentration and no petroleum, and the makeup artist provided some recommendations of her own: Brauer Paw Paw Ointment, Suvana Organic Paw Paw & Honey Balm, and Natural Alternative Paw Paw Ointment.

This will be an interesting one to watch.

Do you use Lucas Papaw Ointment? Why/why not?