This page is a spin off from the Skin Care Forum

The list below is not even a little bit near to complete; it's just a start.

If some of the chemicals in the skin care product that you use / are planning to use, are not listed below, please post the ingredients of that product in this thread, so that I can take a look at them.

Chemicals that are not acceptable in skin care products, in my view, are printed in red, or in pink, if less harmful. Chemicals that are relatively harmless, are printed in green.

Chemicals that I don't want to classify as harmful or harmless, are printed in black.

Chemicals are printed in alphabetical order.

ALLANTOIN

Is an antibiotic, and can therefore impair the balance of bacteria naturally present in the skin.

BUTYLENE GLYCOL

Butylene glycol has neuropharmacological properties, but is not considered carcinogenic

BUTYLPARABEN

Butylparaben has an adverse effect on the secretion of testosterone and on the function of the male reproductive system. Of the parabens, butyl- and isobutylparaben are most toxic.

The parabens are preservatives that may irritate your skin and can cause allergic reactions.

CANDELILLA
Candelilla is considered safe for cosmetic use but can cause skin appendages

CETEARETH 

Ceteareths are the polyethylene glycol (PEG) ethers of Cetearyl Alcohol.

Ceteareth 15 can irritate the skin.

CETEARETH 20 (Eumulgin B3, polyoxyethylene cetylstearyl ether)

Doesn't affect the lipid layer of the skin, but it does increase the absorption of accompanying ingredients into the skin, so these need to be harmless. It may also irritate the skin.

CETEARYL ALCOHOL

It increases viscosity of the product. It is practically non-toxic, but may cause slight skin irritation in some

CETIOL HE

Disturbs the lipid layer of the skin.

CETYL ALCOHOL

It increases viscosity of the product. Practically non-toxic, but may cause slight skin irritation in some

CHLORINE
Likely irritates the skin. Accelerates aging of the skin.

COLOR PIGMENTS (FD & C)
Many color pigments are carcinogenic and cause skin sensitivity and irritation. Certain colors can cause death of skin cells, accelerating the aging process.

CYCLOPENTASILOXANE

Cyclopentasiloxane is a silicone compound. In animals, low amounts already affected uterine functioning.

DIETHANOLAMINE (DEA) 

DEA is usually listed on the ingredient label in conjunction with the compound being neutralized. Thus look for names like Cocamide DEA, Lauramide DEA, etc. It may interfere with your hormone levels.  

DISODIUM EDTA

Is is mildly toxic, but considered safe.

DMDM HYDANTOIN
May cause skin irritations (and irritate the respiratory system and trigger heart palpitations) and (indirectly, by triggering formaldehyde release) cause allergies, depression, headaches, chest pains, ear infections, chronic fatigue, dizziness and loss of sleep, trigger asthma and weaken the immune system.

EUMULGIN B3 (Ceteareth 20, polyoxyethylene cetylstearyl ether)

Doesn't affect the lipid layer of the skin, but it does increase the absorption of accompanying ingredients into the skin, so these need to be harmless. It may also irritate the skin.

ESCULIN
Esculin is not okay because it has water-retaining properties (and therefore they claim it has anti-stretchmark properties)

FRAGRANCE
Many of the compounds in fragrance are toxic. Fragrance may contain up to 4,000 separate ingredients. Symptoms reported to the FDA have included rashes, skin discoloration and allergic skin irritation. Exposure to fragrances can affect the central nervous system. 

GLYCERIN

Both natural and synthetic glycerin are completely harmless

HISTIDINE HYDROCHLORIDE
histidine hydrochloride has toxic properties and is also a growth factor, and can therefore enhance prexisting skin tumours

HYALURONATE SODIUM (Hyalgan, SL-1010)

It has anti-inflammatory properties, and is injected to relieve joint pain (in patients with osteoarthritis). Like corticosteroids, it may cause water retention.

IMIDAZOLIDINYL UREA
May cause skin irritations (and irritate the respiratory system and trigger heart palpitations) and (indirectly, by triggering formaldehyde release) cause allergies, depression, headaches, chest pains, ear infections, chronic fatigue, dizziness and loss of sleep, trigger asthma and weaken the immune system.

ISOBUTYLPARABEN

Of the parabens, Butyl- and Isobutylparaben are most toxic.

ISOPROPYL ALCOHOL
inhalation may cause headaches, flushing, dizziness, mental depression, nausea vomiting, narcosis and even coma. 

ISOSTEARYL ALCOHOL 

It increases viscosity of the product. Doesn't cause skin irritations

JOJOBA OIL / ESTERS

Jojoba oil has slightly toxic properties, but doesn't irritate the skin, except in those that have had eczema before.

JOJOBA WAX

Jojoba-wax is completely hydrogenated jojoba-oil, and hydrogenation may cause harmful fatty acids (check out this page). Jojoba oil has slightly toxic properties, but doesn't irritate the skin, except in those that have had eczema before.

LECITHIN
Lecithin from different sources can elicit allergic / asthma like reactions, and one should therefore carefully monitor one's skin's reaction

METHYLPARABEN (Methyl parahydroxybenzoate)

It is a preservative that may irritate your skin.

A mixture of methyl-, ethyl- and propylparaben exacerbates prexcisting skin complaints.

Methylparaben sodium can affect the activity of B12.

MINERAL OIL
Baby oil is 100% mineral oil. This ingredient coats the skin just like plastic wrap and therefore inhibits the skin's ability to release toxins. 

MYRISTYL ALCOHOL

It increases viscosity of the product. Practically non-toxic, but may cause mild skin irritation in some

MOMOETHANOLAMINE (MEA) 

MEA is usually listed on the ingredient label in conjunction with the compound being neutralized. Thus look for names like Cocamide MEA, Lauramide MEA, etc. It may interfere with your hormone levels. 

OCTYL METHOXCINNAMATE
Octyl Methoxcinnamate stimulates the creation of a 'perfect' (ídeal submicron-) emulsion, and isn't toxic (in these low amounts)

OCTYL SALICYLATE

Octyl salicylate seems to be safe in concentrations below 30%

ORYZANOL
Oryzanol seems not to be carcinogenic (and is considered an 'antioxidant'), but it (though metabolized) does influence your triglyceride (and cholesterol) levels, which is unnacceptable in my view.

PANTHENOL

Panthenol is a so called pro-vitamin (which means that it may be converted into a vitamin by the body, just as beta-carotene may get converted into vitamin A, or cholesterol into vitamin D)
Panthenol may get converted into pantothenic acid (vitamin B5)

PARABEN (Butyl-, Isobutyl-, Ethyl-, Methyl- and Propyl parahydroxybenzoate)

They are preservatives that may irritate your skin and can cause allergic reactions.

A mixture of methyl-, ethyl- and propylparaben exacerbates prexcisting skin complaints.

Butyl- and isobutyl-parabens are more toxic than propyl- and isopropyl-parabens, and ethyl- and methyl-parabens and p-hydroxybenzoic acid are less toxic than propyl-paraben.

PHENOXYETHANOL (Phenoxetol, 2-phenoxyethanol)

Its a practically non-toxic preservative, but also a hospital disinfectant and an anesthetic (on fish), and is rapidly absorbed into the skin. It is neurotoxic in high doses.

(Color) PIGMENTS (FD & C) 
Many color pigments are carcinogenic and cause skin sensitivity and irritation. Certain colors can cause death of skin cells, accelerating the aging process.

PLANKTON EXTRACT

May contain high copper levels and arsenic compounds (and dimethylsulphoxide)

POLYETHYLENE GLYCOL (PEG)

It strips your skin, and therefore causes dehydration and accelerates the aging process.

POLYOXYETHYLENE CETYLSTEARYL ETHER (Ceteareth 20, Eumulgin B3)

Doesn't affect the lipid layer of the skin, but it does increase the absorption of  accompanying ingredients into the skin, so these need to be harmless. It may also irritate the skin.

POLYOXYETHYLENE SORBITAN MONOLAURATE (Polysorbate-20)

It retards the absorption of some accompanying chemicals in the skin, which is good. It is however mildly toxic and may cause skin irritation in some. It can induce present skin tumours.

POLYSORBATE-20 (polyoxyethylene sorbitan monolaurate, Tween 20)

It retards the absorption of some accompanying chemicals in the skin, which is good. It is however mildly toxic and may cause skin irritation in some. It can induce present skin tumours.

PROPOLIS
Propolis influences your triglyceride (and cholesterol) levels, which is unnacceptable in my view.

PROPYLENE GLYCOL (PG)
It breaks down skincells, and therefore accelerates the aging process.

PROPYLPARABEN

A preservative that may irritate your skin. Propylparaben has an adverse effect on the secretion of testosterone and on the function of the male reproductive system.

Bacteria readily adapt to propylparaben. Propylparaben is more extensively absorbed than other parabens. 

SEA BUCKTHORN (Hippophae)

Contains flavones (with different bio-active properties, incl. anti-inflammatory), and can contain thigh levels of toxic metals (zinc, lead, cadmium, iron).

SEAWEED

Contains anti-mutagenic flavonoids, which may have pro-mutagenic properties themselves. May contain high levels of toxic metals (zinc, lead, cadmium, iron).

SODIUM HYALURONATE (Hyalgan, SL-1010)

It has anti-inflammatory properties, and is injected to relieve joint pain (in patients with osteoarthritis). Like corticosteroids, it may cause water retention.

SODIUM LAURYL SULFATE (SLS) 

SODIUM LAURETH SULFATE (SLES)
Breaks down cells, accelerating the aging process. May also cause skin irritation and may be damaging to the skin's immune system. SLS easily penetrates the skin and reaches internal organs, maintaining residual levels in the heart, the liver, the lungs and the brain.

STEARIC ACID

Stearic acid is a completely harmless, natural fatty acid

SUCROSE DISTEARATE

Sucrose Distearate is a sucrose ester, used as an insectiside, and not totally harmless

TOCOPHEROL (Vitamin E)
A too high level of vitamin E (the tocopherol family) accelerates shedding of the skin, which is not good

TRIETHANOLAMINE (TEA)
TEA may interfere with your hormone levels.

ULVA LACTUCA

This algae may contain high levels of toxic metals (manganese, iron, zinc, cadmium, copper).

WATERCRESS EXTRACT

Watercress contains flavonoids with anti-mutagenic properties, but that isn't necessarily good, as they can elicit pro-mutagenic (DNA-damaging) properties themselves.