Risky Henna
First of all, there is no such thing as 'black henna'. Henna is not black. It is not made from a different part of the plant. Anyone who tells you this is either misinformed or lying to you. Only the leaves are used for dying skin.
The worst culprits for chemical laced harmful henna are the pre-made cones that come from a factory. Some 'henna' powders may contain chemical dyes as well.
There are three things a factory made henna cone can be:
- Full of chemical dyes
- Full of nasty preservatives
- Stale.
Henna is a PERISHABLE PRODUCT. It is not shelf stable. When you make fresh henna at home it will go off in a matter of days if left it on your kitchen bench. So how do these cones travel here from overseas, sit on a shelf in a store for months, then leave a stain on your skin?
Best case scenario - it won't. The best you can hope for is the last off the above list - Stale. It IS natural henna, but will no longer be a viable product. This kind of henna won't hurt you, but it will be disappointing to use.
The other two on the above list are another kettle of fish. There may actually be henna present, but it is not alone. Sometimes it is simply a gel with no henna at all. Henna has become a catch-all term to describe any temporary body art in some places. Chemical colourants used in these products are not approved for use on skin. Some are approved for use in hair dye, but at much lower concentrations. Some will contain high concentrations of food dyes. This does not mean they are safe, in fact these dyes have been banned in most countries and were never meant to be used in such concentrations in the first place.
But I'm not eating it! How can that hurt?
Your skin is permeable. This means that some things can pass through your skin and enter your bloodstream. Poisonous things that can do this are called transdermal toxins. Trans means across, and dermal means skin. So it can pass through the skin and get into your blood and is carried all around your body, harming your organs as it goes. In some ways this is worse than eating a substance, because your body will often deal with harmful things quickly by vomiting or speeding up it's passage through your digestive system.
A transdermal toxin bypasses this potentially protective mechanism and directly enters your bloodstream. It is bad news in all sorts of ways.
Other colourants that are used in henna style products are industrial dyes like paraphenylediamine (PPD). This is used mostly in hair dyes (always in dark permanent colours, often also in semi/demi permanent colours) but also used to colour textiles and fur, newspaper print, printer ink, and black rubber as a few examples. PPD in hair dye is used in low, carefully regulated concentrations. Even then, an allergy test is always recommended, and the product should not come into contact with the skin (or as little as is possible).
This is because PPD is also a transdermal toxin, and can also cause allergic reactions.
These are black henna injuries. Black henna injuries are chemical burns and can also progress to a full allergic reaction, including closing of airways. Often skin reactions become permanent scars.
Not everyone will have a skin reaction to the chemical. But it still enters your body through your skin and puts you at a higher risk of bladder and liver cancer. This is the reason hairdressers have a higher incidence of these cancers.
PPD is also what is called a sensitizing agent. Every time you have an exposure to it, you are more likely to react to it. So just because you may have had one or two or ten black henna designs without a visible problem, you never know when you will reach your threshold and end up with something like the horrible injuries above.
Finally, the preservatives and other ingredients in factory made henna can include petrol, kerosene, turpentine, benzene to name a few. These can also cause burns on your skin and are NOT the sort of thing you want on your body. Do not trust labeling on these imported products, as they are not accurate and can be deliberately misleading.
How can I know if a product is safe? Natural henna will meet ALL FOUR of these criteria.
1. smell.
Henna should not smell like hair dye or petrol or any other obviously chemical scent. It may smell like essential oils such as eucalyptus, tea tree, lavender, or it may smell earthy.
2. look.
Henna is a greenish brown paste. It may even look a little golden depending on the region it is grown in. As the paste dries it will become very dark brown and will possibly look black in photos while the paste is still on the skin. Henna paste is raised, black 'henna' gels tend to dry mostly flat.
3. result.
If someone is doing henna for you, ask them how long to leave it on, and what colour it will be when the paste comes off. Natural henna will need to be on for a couple of hours (at a minimum!), and will be orange when it comes off. Any other colour is NOT natural henna. Remember, this initial colour is no guarantee that it will not contain harmful solvents.
4. storage
Ask your artist how they store their henna when they're not using it. Natural henna needs to be kept cold. If they tell you they make it fresh for each event, that's great! It's probably natural henna. If they say they keep it in the fridge or freezer, that's awesome too. It's good news, and indicates it's probably natural. If they say they keep it in the cupboard or any other unrefrigerated location, be cautious. It may have unknown chemical preservatives.
Please share this information with your friends and loved ones, especially if they are planning overseas travel, particularly to Bali, Mexico, Turkey, and the USA. Henna is a beautiful plant and tradition and it would be a shame for it to die out because of the actions of the unscrupulous.