Giuliani Scabiacid 5% Cream Permetrina

The cosmetic grade stuff is highly refined with a solid safety record. The CIR Expert Panel has repeatedly reaffirmed this ingredient to be safe in current practices of use and concentration.

The worry about carcinogenic compounds only applies to industrial grades, not the purified version used in skincare.

Despite its reputation, the highly reformed form is non-comedogenic and doesn't penetrate deeply into skin.

The good news for fungal-acne prone folks: the Malassezia yeast feeds on fatty acids and lipids and paraffin doesn't contain any of these (so there's nothing for the yeast to metabolize). This ingredient is considered fungal acne safe.

Typical use ranges from 0.5-30%. Most leave-on products are in the 1-10% zone.

The 20 ethylene oxide units is well above the PEG-10 threshold and therefore not a food source for Malassezia (it's fungal acne safe).

This ingredient has a comedogenic rating of 2 and an irritancy rating of 3. These numbers come from testing the raw ingredient on rabbit ears and doesn't reflect how it will behave in a finished product.

In practice, this ingredient is a well-tolerated ingredient. The ratings reflect cautious lab conditions and not real-world use. Just be sure to patch test any formulas you feel unsure about.

This ingredient is generally considered non-toxic, non-irritating, and has low absorption potential.

You might have heard that this ingredient clogs pores. This reputation comes from the older rabbit ear studies which are more sensitive than human skin to clogging.

Dermatologist Dr. Zoe Draelos has also confirmed in a peer-reviewed paper that products containing comedogenic ingredients are not necessarily comedogenic themselves.

A small subset of people (~2%) may experience contact sensitivity so patch testing is a reasonable idea if you have reactive skin.

Since this ingredient is an ester of myristic acid (a C14 fatty acid), it falls within the carbon chain range that is known to feed Malassezia. This ingredient may not be fungal acne safe.

As a preservative, it works by disrupting the membrane of microbial proteins. This helps keep bacteria and fungi from growing in your products.

The sensitization picture is actually quite assuring as well:of nearly 71,000 patients patch tested with benzyl alcohol, only 0.21% showed a positive reaction with most of them being weakly positive.

This led researchers to conclude that benzyl alcohol cannot be regarded as a significant contact allergen.

It is worth noting this ingredient is classified as one of the EU's regulated fragrance allergens and restricted to 1% in finished products.

Labels must also declare it in concentrations above 0.001% in leave-on products and 0.01% in rinse-off products.

At concentrations around 5%, localized redness and itching can appear as a direct irritant response and not as a true allergic reaction.

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