Category Archives: Preservatives

Preservatives in Natural Products: Honeysuckle and Japanese Honeysuckle Extracts

This post has been LONG in the making. Look for more regular Preservatives posts in the future!

The primary focus of Nature’s Pulchritude is to educate. This post is the seventh in a series of in depth posts that will educate you about the various preservatives in hair and skin products, as well as their potential toxicity.

PURPOSE

Preservatives are added to cosmetics, personal care products, and food to maintain a products integrity and stability by inhibiting or reducing the growth of microorganisms such as bacteria and fungus (FDA).  Most products sold via retail sit for extended periods of time during shipping, in a warehouse, and on store shelfs that allow enough time for a product to spoil or cause microbial growth which render the product unfit for use.  This is particularly true for products that contain water, such as many conditioners and moisturizers, and other active ingredients (antioxidants and emulsifiers) that would otherwise lose their effectiveness and stability over time.

Preservatives are chosen in cosmetics based on a variety of factors which include ability to inhibit growth over a broad spectrum and method of derivation (natural vs. synthetic).  Preservatives tend to be in concentrations less than 2% of the weight of the formula, however, widespread use of potentially harmful preservatives, such as parabens, has been a great cause of concern for some scientists and consumers.  The Food, Drug, and Cosmetic Act does not grant the Food & Drug Administration the authority to regulate the use of preservatives unless it is known to be “poisonous or deleterious” (FDA).

HONEYSUCKLE AND JAPANESE HONEYSUCKLE EXTRACTS

Honeysuckle extract and Japanese Honeysuckle extract are made from two different species of Honeysuckle flowers, Lonicera caprifolium and Lonicera japonica, respectively.  It is typically extracted via alcohol or 100% carbon dioxide.  Honeysuckle and Japanese Honeysuckle contain a variety of phytochemicals.  Japanese Honeysuckle contains Methyl Caffeate (C10H10O4), 3,4-di-O-caffeoylquinic acid, methyl 3,4-di-O-caffeoylquinate, protocatechuic acid (C7H6O4), chrysin (C15H10O4) methyl chlorogenic acid, hyperoside (C21H20O12), chlorogenic acid (C16H18O9), caffeic acid (C9H8O4), and luteolin (C15H10O6) (Rahman and Kang 2009).  Many of these phytochemicals have anti-inflammatory and antioxidant benefits.  Honeysuckle and Japanese Honeysuckle both contain parahydroxybenzoic acid (4-Hydrobenzoic Acid), which goes through a process of esterification to produce synthetic parabens.

Molecular Stucture of parahydroxybenzoic acid

Honeysuckle and Japanese Honeysuckle are used as preservatives due to their antiviral and antibacterial phytochemicals.  Honeysuckle extract can be found independent of Japanese Honeysuckle extract, and is recommended to be used in concentrations of 5-10% of the formula. Honeysuckle and Japanese Honeysuckle are often sold as a blend, ratio uncertain, for use as a preservative, and is suggested to be used in concentrations of 0.5-2% of the formula.  Given the difference in recommended use, it is likely Japanese Honeysuckle (Lonicera japonica) has the higher antimicrobial content. Japanese Honeysuckle and Honeysuckle extracts have demonstrated the ability to deter microbial growth in acidic, low water environments for gram-positive and gram-negative Bacteria, though they are not as effective against mold (Papageorgiou et al. 2009). Another study done in 2009 yielded similar results, showcasing the strong antimicrobial activity of Japanese Honeysuckle (Rahman and Kang 2009).

Hazards
The primary concern surrounding Honeysuckle extract and Japanese honeysuckle extract is that the extracts contain or are ‘parabens.’ This is a misnomer. Neither extract is known to contain parabens. It is important to make the clear distinction between parahyrdoxybenzoic acid and parabens, as parabens are a synthetic chemical designed to mimic parahydroxybenzoic acid (esters). Parahydroxybenzoic acid is a phytochemical present in a variety of fruits and vegetables including blueberries, cucumbers, and olives. It is assumed that parahydroxybenzoic acid accumulates in cancerous tissues similar to parabens, however, there is no literature that supports or disproves this. The exact composition of Honeysuckle extract and Japanese Honeysuckle extract depends on the manufacture, therefore contamination with other preservatives or chemicals is a possibility. A 2012 study found Japanese Honeysuckle extract to be contaminated for formaldehyde, which resulted in the aggravation of existing allergic contact dermatitis caused by formaldehyde releasers and fragrances (Gallo et al. 2012). It is believed the Japanese Honeysuckle extract leached the formaldehyde releasers from epoxy or phenolic-based plastic packaging (Gallo et al. 2012).

CONCLUSIONS

There is presently to published literature that states that the parahydroxybenzoic acid content of Honeysuckle extract and Japanese Honeysuckle extract behaves similar to parabens (accumulating in the body, being an endocrine disruptor, mimic oestrogen), however, this is a possibility.  More research should be done on these extracts and their parahydroxybenzoic acid content to further establish their safety.  Honeysuckle extract and Japanese Honeysuckle extract both contain a vast variety of phytochemicals that are known to have anti-inflamitory, antimicrobial, antiviral, and anti-cancer properties among other benefits.  If you have concerns about Honeysuckle extract or Japanese Honeysuckle extract it is best to err on the side of caution.

BHT: Friend or Foe?

BHT is moderately common food additive, and a seldom used cosmetic preservative.  BHT is an acronym for butylated hydrotoluene.  Though BHT is not used in natural or organic products, it is moderately used in a variety of food and cosmetic products, some of which are primarily marketed for children and young adults.  BHT is typically the last ingredient listed and looks rather harmless abbreviated as opposed to its full chemical name which would certainly cause consumer to question their purchase.

Butylated hydrotoluene is a chemical derivative of phenol (-OH group attached to a benzene ring) and can be described as a lipophilic (likely to bind to fat) organic compound that is widely used across various industries for its antioxidant properties.  Specifically, butylated hydrotoluene reacts with oxygenating free radicals to decrease the rate of autoxidation.  BHT has a low molecular weight (220.35 grams/mole), which means it can have the ability to be absorbed through the skin when applied topically.  Despite being used in very low concentrations that typically do not exceed 0.1% of a food product, BHT still poses various health concerned when consumer internally or applied topically.  Though BHT is not officially listed as a carcinogen, is is suspected of carcinogenic activity, is known to be mutagenic to mamalian reproductive (somatic) cells, and is toxic to the blood, liver, and central nervous system.  While antioxidants and other preservatives are beneficial in preventing food or product spoilage, why is a food and cosmetic additive with a questionable safety reputation still being used, particularly in vulnerable populations such as children?

BHT is suspected of causing rodent carcinogenic activity, therefore, being slow growing and malignant (Parke & Lewis 2009).  BHT has also been shown to exacerbate chronic urticaria, a rash or red welts that develop from food allergies (Goodman et al. 1990).  A 2000 study found that BHT consumption at low levels did not lead to incidence of stomach cancer, though BHT intake was only measured from mayonnaise and salad dressing intake (Botterweck et al. 2000).  Though there is no concrete evidence of carcinogenicity of BHT in humans, it is usually best to err on the side of caution.  There are limited studies that observed the effects of BHT from cereals or other foods in children.  The suspicion of carcinogenic activity should not be taken lightly.  For that reason butylated hydroxytoluene (BHT) is a ‘foe.’

 

Have you used a product or eaten a food with BHT?

Are there any ingredients (food or cosmetics) you would like to see featured in Friend or Foe?  Leave a comment below or send us an e-mail!

Preservatives in Natural Products: Benzyl Alcohol

The primary focus of Nature’s Pulchritude is to educate.  This post is the fifth in a series of in depth posts that will educate you about the various preservatives in hair and skin products, as well as their potential toxicity.

PURPOSE

Preservatives are added to cosmetics, personal care products, and food to maintain a products integrity and stability by inhibiting or reducing the growth of microorganisms such as bacteria and fungus (FDA).  Most products sold via retail sit for extended periods of time during shipping, in a warehouse, and on store shelfs that allow enough time for a product to spoil or cause microbial growth which render the product unfit for use.  This is particularly true for products that contain water, such as many conditioners and moisturizers, and other active ingredients (antioxidants and emulsifiers) that would otherwise lose their effectiveness and stability over time.

Preservatives are chosen in cosmetics based on a variety of factors which include ability to inhibit growth over a broad spectrum and method of derivation (natural vs. synthetic).  Preservatives tend to be in concentrations less than 2% of the weight of the formula, however, widespread use of potentially harmful preservatives, such as parabens, has been a great cause of concern for some scientists and consumers.  The Food, Drug, and Cosmetic Act does not grant the Food & Drug Administration the authority to regulate the use of preservatives unless it is known to be “poisonous or deleterious” (FDA).

BENZYL ALCOHOL
Chemical Structure of Benzyl Alcohol

Benzyl alcohol is an aromatic (stabilized ring of atoms) alcohol.  Benzyl alcohol is a natural component of many fruits, and is also present in the essential oils of plants such as jasmine and hyacinth.  It is also produced synthetically via the hydrolysis (breakdown of a compound due to reaction with water) of benzyl chloride (C6H5CH2Cl) and sodium hydroxide [lye] (NaOH).  The byproduct of this reaction is benzyl alcohol (C6H5CH2OH) and salt (NaCl).  Benzyl alcohol can also be produced by reacting phenylmagnesium bromide (C6H5MgBr) with formaldehyde (CH2O), which is a known carcinogen.  Benzyl alcohol is used in cosmetics as a bacteriostatic (prevents the growth of bacteria without destroying it) preservative.  Benzyl alcohol is a known skin sensitizer and may also trigger a variety of deleterious effects.  Use of benzyl alcohol is limited to 1% in the EU when used as a preservative, 0.001% and 0.01% when used as a fragrance in leave-on and rinse-off products respectively.  It is limited to 5% in the US.

Hazards
Benzyl alcohol was present in 9% of 204 tested cosmetics products (92 shampoos, 61 conditioners, 34 liquid soaps, and 17 wet tissues), making it the 12th most abundant preservative detected, tied with potassium sorbate (Yazar et al. 2010).  Benzyl alcohol was an ingredient in 24% of 276 moisturizers contained in a database of moisturizers sold at a common drugstore and was the 5th most common allergen (Zirwas and Stechschulte 2008).  Benzyl alcohol is considered an uncommon contact allergen, though it can occur with repeated topical medication or moisturizer use (Zirwas and Stechschulte 2008).  It is most commonly associated with deleterious effects when injected.  Benzyl alcohol was a common preservative in intravascular flush solutions administered to infants, which resulted in “neurologic deterioration and death” in infants with low birth weights (Hiller et al. 1986).  Benzyl alcohol is not likely to cause developmental or reproductive toxicity nor carcinogenicity, though they are suspected mutagens (tests have not confirmed this) (CIR 2011).  It is typically used in concentrations between 0.000006% to 10%, with hair color having the highest concentration.  It has been shown to be a skin irritant or skin sensitizer at 1%concentration in 0.54% and 0.4% of patients, respectively, as well as in 0.3% of patients in a separate study at the same concentration.  It was a skin irritant in 4.9% of patients at 5% concentration (CIR 2011).  It is considered safe up to concentrations of 5% (Nair et al. 2001).

CONCLUSIONS

Benzyl alcohol is a relatively safe preservative when used in cosmetics.  It is not likely to cause dermal toxicity nor is it likely to cause skin irritation or sensitization. Various studies show low rates of irritation and sensitization at 1% and 5% concentration which are within range of allowable usage in cosmetics.  It is not believed to be a carcinogen or a developmental/reproductive toxin in studies.  It is not as common as many other preservatives, though it is more often used in products marketed as natural and organic.  The biggest risk associated with benzyl alcohol is via injection in infants.

 

 

References

Cosmetic Ingredient Review.  2011.  “Amended final safety assesment: benzyl alcohol, and benzoic acid and its salts and benzyl ester.”  CIR.  i-38.

Hiller J., Benda, G., Rahatzad, M., Allen, J., Culver, D., Carlson, C., and J. Reynolds.  1986.  “Benzyl alcohol toxicity:  impact on mortality and intraventricular hemorrhage among very low birth weight infants.”  Pediatrics.  77(4):500-506.

Nair, B., Bergfeld W., Belsito D., Snyder P., Klaassen C., Schroeter A., Shank R., Slaga T., and F. Andersen.  2001.  “Final report on the safety assessment of benzyl alcohol, benzoic acid, and  sodium benzoate.”  International Journal of Toxicology. 20: 23‐50.

Yazar, K., Johnsson, S., Lind, M., Boman, A., and C. Liden.   2010. “Preservatives and fragrance in selected consumer-available cosmetics and detergents.”  Contact Dermatitis.  64: 265-272.

Zirwas, M. and S. Stechschulte.  2008.  “Moisturizer Allergy.”  Journal of Clinical and Aesthetic Dermatology.  1(4): 38-44.

Preservatives in Natural Products: Potassium Sorbate

The primary focus of Nature’s Pulchritude is to educate. This post is the fourth in a series of in depth posts that will educate you about the various preservatives in hair and skin products, as well as their potential toxicity.

PURPOSE

Preservatives are added to cosmetics, personal care products, and food to maintain a products integrity and stability by inhibiting or reducing the growth of microorganisms such as bacteria and fungus (FDA).  Most products sold via retail sit for extended periods of time during shipping, in a warehouse, and on store shelfs that allow enough time for a product to spoil or cause microbial growth which render the product unfit for use.  This is particularly true for products that contain water, such as many conditioners and moisturizers, and other active ingredients (antioxidants and emulsifiers) that would otherwise lose their effectiveness and stability over time.

Preservatives are chosen in cosmetics based on a variety of factors which include ability to inhibit growth over a broad spectrum and method of derivation (natural vs. synthetic).  Preservatives tend to be in concentrations less than 2% of the weight of the formula, however, widespread use of potentially harmful preservatives, such as parabens, has been a great cause of concern for some scientists and consumers.  The Food, Drug, and Cosmetic Act does not grant the Food & Drug Administration the authority to regulate the use of preservatives unless it is known to be “poisonous or deleterious” (FDA).

POTASSIUM SORBATE
Chemical Structure of Potassium Sorbate

Potassium Sorbate is the potassium salt (neutralization reaction of an acid and a base) of sorbic acid. It is created by using potassium hydroxide (KOH) to neutralize sorbic acid (C6H8O2). Sorbic acid is naturally occurring in the rowan berry, however, it is primarily produced synthetically. Potassium Sorbate (C6H7KO2) is a common food and wine preservative that is used to inhibit the growth of mold and yeast, and is also used in various personal care products. Potassium sorbate has been regarded as a safe replacement for parabens in cosmetics and personal care products. Potassium sorbate is believed to have a long safety record, though it can be a cause of concern. Use of sorbic acids and its salts (potassium sorbate) are limited to 0.6% by the EU.

Hazards
Potassium sorbate was found in 9% of 204 tested cosmetics products (92 shampoos, 61 conditioners, 34 liquid soaps, and 17 wet tissues), making it the 12th most abundant preservative detected (Yazar et al. 2010).  Potassium sorbate is considered generally safe by the FDA, and has been found to be relatively non-toxic. A study conducted in 1990 found potassium sorbate to show “a very low level of mammalian toxic,” even at up to 10% of the diet, devoid of carcinogenic activity, and non-mutagenic in in vitro and in vivo tests (Walker 1990).  Potassium sorbate is also considered a nonirritant to the eyes and only slightly irritating to the skin.   In contrast, a 1992 study found potassium sorbate to be a low-level mutagen, which supported studies from 1977 that found similar results in in vitro hamster cells (Würgler et. al 1992).  Additionally,  2010 study found potassium sorbate to be genotoxic to human peripheral (close to surface) blood lymphocytes (white blood cell) in vitro, causing damage to DNA (Mamur et al. 2010).

CONCLUSIONS

Potassium sorbate is considered one of the safest synthetic preservatives used in cosmetics.  By and large, potassium sorbate is regarded as generally safe, is not a carcinogen and has relatively low toxicity and mutagenic activity.  As of 2006, the Cosmetic Ingredient Review lists potassium sorbate as safe for use in cosmetics and did not find it to be mutagenic within accepted guidelines (0.00003% – 0.7%) (CFTA 2006; CIR 2008).  It is a prevalent preservative in food as compared to cosmetics.  Only one of the papers specifically researched potassium sorbate in cosmetics, and that paper did not go into detail about deleterious effects of it as a preservative.  Additional research should be done on the toxicity of potassium sorbate in cosmetics and personal care products.  There is a chance that dermal exposure could be just as or more harmful than oral exposure, but there is presently no information to support that possibility.

 

References

Cosmetic Ingredient Review.  2008.  “Annual review of cosmetic ingredient safety assessments: 2005/2006.” International Journal of Toxicology.  27(Supp. 1): 77-142.

Mamar,S., Yüzbaşıoğlu, D., Ünal, F., and S.  Yılmaz.  2010.  “Does potassium sorbate induce genotoxic or mutagenic effects in lymphocytes?”  Toxicology in Vitro.  24(3): 790-794.

Yazar, K., Johnsson, S., Lind, M., Boman, A., and C. Liden.   2010. “Preservatives and fragrance in selected consumer-available cosmetics and detergents.”  Contact Dermatitis.  64: 265-272.

Walker, R.  1990.  “Toxicology of sorbic acid and sorbates.”  Food Additives and Contaminants. 7(5): 671-676.

Würgler, F.E., Schlatter K., and P. Maier.  1992.  “The genotoxicity status of sorbic acid, potassium sorbate and sodium sorbate.”  Mutation Research.  283: 107-111.

 

Preservatives in Natural Products: Phenoxyethanol

The primary focus of Nature’s Pulchritude is to educate. This post is the fourth in a series of in depth posts that will educate you about the various preservatives in hair and skin products, as well as their potential toxicity.

PURPOSE

Preservatives are added to cosmetics, personal care products, and food to maintain a products integrity and stability by inhibiting or reducing the growth of microorganisms such as bacteria and fungus (FDA).  Most products sold via retail sit for extended periods of time during shipping, in a warehouse, and on store shelfs that allow enough time for a product to spoil or cause microbial growth which render the product unfit for use.  This is particularly true for products that contain water, such as many conditioners and moisturizers, and other active ingredients (antioxidants and emulsifiers) that would otherwise lose their effectiveness and stability over time.

Preservatives are chosen in cosmetics based on a variety of factors which include ability to inhibit growth over a broad spectrum and method of derivation (natural vs. synthetic).  Preservatives tend to be in concentrations less than 2% of the weight of the formula, however, widespread use of potentially harmful preservatives, such as parabens, has been a great cause of concern for some scientists and consumers.  The Food, Drug, and Cosmetic Act does not grant the Food & Drug Administration the authority to regulate the use of preservatives unless it is known to be “poisonous or deleterious” (FDA).

PHENOXYETHANOL

This ingredient first came to my attention as I was researching companies to feature in The Globes. This ingredient was literally used in over 90 percent of the brands I had been researching, whether under ‘phenoxyethanol’ or as OptiphenTM which is a mixture of phenoxyethanol and Caprylyl Glycol. All of the products I was researching were of course marketed as using natural ingredients, though not certified organic. The first questions I had were “what is it?” and “is it safe?” This ingredient became the inspiration for these series of posts. An ingredient that appears to be so widely used in a niche market should be further investigated.

Chemical Structure of 2-Phenoxyethanol

Phenoxyethanol is a glycol ether made from alkyl ethers of ethylene glycol, though it can be derived from natural sources. Also known as Ethylene glycol monophenyl ether, it is a bactericide (kills bacteria) that is used in cosmetics, pharmaceuticals, and vaccines. Phenoxyethanol (C8H10O2) has increased in usage over that past 5 years because it is a much safer alternative to formaldehyde releasing preservatives and does not have the same negative connotation as parabens. However, phenoxyethanol is not without its own concerns. It use is limited to 1% in Japan and the EU, and it is not suggested for use in baby products as per a warning issued by the FDA.

Hazards
Phenoxyethanol was present in 39% of 204 tested cosmetics products (92 shampoos, 61 conditioners, 34 liquid soaps, and 17 wet tissues), making it the second most abundant preservative detected (of 30), behind methylparaben (Yazar et al. 2010).  Though its use is limited in the EU and Japan to 1%, the Food and Drug Administration (FDA) of the US found that phenoxyethanol “can depress the central nervous system” and “may cause vomiting and diarrhea, which can lead to dehydrating in infants” based on research conducted on a nipple cream for nursing mothers in 2008.  This should be of some concern to mothers who are using products containing phenoxyethanol.  Though the primary pathway is via ingestion, it is always best to exercise caution.

On the contrary, the Cosmetic Ingredient Review declared that phenoxyethanol is “practically non-toxic” to humans when administered orally or through the skin (Lee et al. 2007).  Phenoxyethanol maybe more toxic to infants than adults, though this has not be substantiated based on available literature.  Based on a series of patch tests, Lee et al. found that phenoxyethanol, as well as parabens, can cause sensory irritation of the skin, which typically results in “stinging, burning, and itching that occur[s] without visual signs of skin inflammation” (2007).  Phenoxyethanol was also found to induce urticaria and eczema, a rash of red welts accompanied by itching, in patch tests at 1% after 3 individuals experienced skin irritation after using a product with the preservative (Bohn and Bircher 2008).  However, these reactions (hypersensitivity) from cosmetics is considered very rare.  Phenoxyethanol in the presence of other preservatives can increase risk of allergic reaction (Lee et al. 2007).

CONCLUSIONS

Phenoxyethanol is considered safer than many available preservatives.  It is not known to be toxic in humans, though it can be a skin irritant in some individuals.  This ingredient was previously allowed in products certified organic in the UK by ECOCERT, however, this is no longer a common practice.  While this product itself is not natural, it does serve its purpose as a preservative.  As with the other preservatives covered, it is not without its flaws, however, it appears much safer than other preservatives and is not suspected to be carcinogenic in humans.  Consumers with children should be the most cautious of this ingredient and should do their best to ensure that their child does not consume a product containing this ingredient and limit exposure overall.

References:

Bohn, S. and A. Bircher.  2008.  “Phenoxyethanol-induced urticaria.”  European Journal of Allergy and Clinincal Immunology.  56(9): 922-923.

Lee, E., An, S., Choi, D.,  Moon, S., and I. Chang.  2007.  “Comparison of objective and sensory skin irritations of several cosmetic preservatives.”  Contact Dermatitis.  56: 131-136.

Yazar, K., Johnsson, S., Lind, M., Boman, A., and C. Liden.   2010. “Preservatives and fragrance in selected consumer-available cosmetics and detergents.”  Contact Dermatitis.  64: 265-272.

 

Preservatives in Natural Products: Sodium Benzoate

The primary focus of Nature’s Pulchritude is to educate. This post is the third in a series of in depth posts that will educate you about the various preservatives in hair and skin products, as well as their potential toxicity.

PURPOSE

Preservatives are added to cosmetics, personal care products, and food to maintain a products integrity and stability by inhibiting or reducing the growth of microorganisms such as bacteria and fungus (FDA).  Most products sold via retail sit for extended periods of time during shipping, in a warehouse, and on store shelfs that allow enough time for a product to spoil or cause microbial growth which render the product unfit for use.  This is particularly true for products that contain water, such as many conditioners and moisturizers, and other active ingredients (antioxidants and emulsifiers) that would otherwise lose their effectiveness and stability over time.

Preservatives are chosen in cosmetics based on a variety of factors which include ability to inhibit growth over a broad spectrum and method of derivation (natural vs. synthetic).  Preservatives tend to be in concentrations less than 2% of the weight of the formula, however, widespread use of potentially harmful preservatives, such as parabens, has been a great cause of concern for some scientists and consumers.  The Food, Drug, and Cosmetic Act does not grant the Food & Drug Administration the authority to regulate the use of preservatives unless it is known to be “poisonous or deleterious” (FDA).

SODIUM BENZOATE
Chemical Structure of Sodium Benzoate

Sodium Benzoate is a common preservative in many products that market themselves as being ‘natural’ or ‘organic.’  Sodium Benzoate is a sodium salt of benzoic acid, which is naturally occurring in apples, cranberries, plums, ripe cloves, and cinnamon in low levels, and is often produced synthetically by reacting Benzoic Acid with Sodium Hydroxide (NaOH).  Sodium Benzoate (NaC7H5O2) is used as a food, medicine, and cosmetic preservative as a bacteriostatic and fungistatic, both of which reduce or limit the growth or bacteria or fungi by interacting with protein production, metabolism and DNA replication, without otherwise harming the bacteria or fungi.  Its use is limited as a preservative by the FDA to 0.1% of a formula by weight.  Sodium Benzoate is generally regarded as safe by the FDA, however, when combined with ingredients such as Vitamin C or E it can react to form benzene, a known carcinogen.

Hazards

Sodium Benzoate was found to be present in 34% of 204 tested products (92 shampoos, 61 conditioners, 34 liquid soaps, and 17 wet tissues) (Yazar et al. 2010).  Though the FDA limits the use of sodium benzoate to 0.1% by weight in food, it is limited to 2.5% in rinse off products and 0.5% in leave on products by the European Union Cosmetic Directive (Yazar et al. 2010).  Though Sodium Benzoate is generally considered safe, it can become a serious hazard if it is combined with Vitamin C (ascorbic acid) or Vitamin E (tocopherols) as they react to form benzene (C6H6), a cancer causing hydrocarbon.  The amount of benzene produced from these reactions was determined to be below dangerous levels (5 parts per billion) for consumption by the World Health Organization, based on presence of benzene in soft drinks.  Benzene is classified as an A1 carcinogen (confirmed for humans) by the American Conference of Governmental Industrial Hygienists (ACGIH) and Group 1 carcinogen by the International Agency for Research on Cancer (IARC).  Benzene is also a possible mutagen and developmental toxin in humans that is specifically toxic to blood, bone marrow, and the central nervous system, and may target the liver and urinary system.  Limited studies show that after dermal (skin) exposure, benzene was metabolized by the liver and excreted.  There is no available research on the formation and concentration of benzene in cosmetic products at this time, so it is best to avoid products containing sodium benzoate in conjunction with ascorbic acid (Vitamin A) or tocopherol (Vitamin E).

CONCLUSIONS

Sodium Benzoate appears to be a safer alternative to some commonly used preservatives on the market.  Despite being a synthetic chemical used in ‘natural’ and ‘organic’ products, it serves its purpose as a preservative without exposing consumers to negative impacts under ideal conditions.  It is not known as an allergen or sensitizer, nor is it itself toxic in the concentrations used in food and cosmetics.  The largest concern with this chemical is its reaction with Vitamin C and Vitamin E to form carcinogenic benzene.  Otherwise, it appears safe in cosmetics.

 

References

Yazar, K., Johnsson, S., Lind, M., Boman, A., and C. Liden. 2010. “Preservatives and fragrance in selected consumer-available cosmetics and detergents.”  Contact Dermatitis.  64: 265-272.

 

Do any of your products or foods contain Sodium Benzoate?  Do they also contain Vitamin C or E?

Preservatives in Natural Products: Methylisothiazolinone and Methylchloroisothiazolinone

THIS POST IS IN THE PROCESS OF BEING UPDATED. 

(As of 6/6/2015)

The primary focus of Nature’s Pulchritude is to educate. This post is the second in a series of in depth posts that will educate you about the various preservatives in hair and skin products, as well as their potential toxicity.

PURPOSE
Preservatives are added to cosmetics, personal care products, and food to maintain a products integrity and stability by inhibiting or reducing the growth of microorganisms such as bacteria and fungus (FDA). Most products sold via retail sit for extended periods of time during shipping, in a warehouse, and on store shelfs that allow enough time for a product to spoil or cause microbial growth which render the product unfit for use. This is particularly true for products that contain water, such as many conditioners and moisturizers, and other active ingredients (antioxidants and emulsifiers) that would otherwise lose their effectiveness and stability over time.

Preservatives are chosen in cosmetics based on a variety of factors which include ability to inhibit growth over a broad spectrum and method of derivation (natural vs. synthetic). Preservatives tend to be in concentrations less than 2% of the weight of the formula, however, widespread use of potentially harmful preservatives, such as parabens, has been a great cause of concern for some scientists and consumers. The Food, Drug, and Cosmetic Act does not grant the Food & Drug Administration the authority to regulate the use of preservatives unless it is known to be “poisonous or deleterious” (FDA).

ISOTHIAZOLINONE DERIVED PRESERVATIVES

Isothiazolinone is a heterocyclic (‘ring’ containing more that 1 element) chemical compound of which its derivatives are typically used as antimicrobial agents and biocides in a variety of personal care products including hair conditioners, shampoos, foundations, eyeliners, mascaras, lotions, and soaps.  The most commonly used isothiazolinone group preservatives are Methylisothiazolinone and Methylchloroisothiazolinone, which have been in use since the 1970’s.  Methylisothiazolinone (MIT) has an ethane (CH3) molecule attached to a Nitrogen (N) atom, whereas Methylchloroisothiazolinone (MCI) has a Chlorine (Cl) atom attached to the ring in addition to the ethane molecule.  Use of MIT and MCI have increased in recent years, perhaps in part to the decline in paraben use, which has resulted in an increase of reported sensitization incidences caused by using products containing these two preservatives.  Allergic contact dermatitis is a common indicator of sensitization from MIT and MCI, which is an immunotoxic response that can cause rashes or skin lesions.  Allergic contact dermatitis has been observed as a result of sensitization to MIT and MCI since the late 1980s.

Methylisothiazolinone Chemical Structure
Methylchloroisothiazolinone Chemical Structure

Hazards

Methylisothiazolinone (MIT) and Methylchloroisothiazolinone (MCI) are often used in conjunction as preservatives.  A 2010 study found that MIT/MCI were present in 23% of 204 tested products (92 shampoos, 61 conditioners, 34 liquid soaps, and 17 wet tissues) (Yazar et al. 2010).  Despite MCI/MIT being allowed in personal care products up to 0.00075% (leave-on) or 0.0015% (rinse off) in the United States, there has been a significant incidence of allergic contact dermatitis from sensitization from these products (Yazar et al. 2010; Castanedo-Tardana and Zug 2013).  The frequency of an MIT allergy is approximately 1.5% in Europe, 3.5%-6.5% in an Australian study (tested 653 patients); the rate is unknown in the United States (Castanedo-Tardana and Zug 2013; Boyapati et al. 2013).  It is very interesting and troubling to know that a preservative at a very low concentration (7.5-15 parts per million) can yield such an allergic response, to the extent that it was named Contact Allergen of the Year by the American Contact Dermatitis Society in 2013 (Castanedo-Tardana and Zug 2013).  This is a prime example that certain ingredients being in low concentration does not always equate their safety, particularly when they are present in products that are used multiple times a day, therefore a continuous low exposure (Yazar et al. 2010).  Once skin has become sensitized, it will continuously react to exposure despite the dosage.  MIT and MCI are often used in conjunction with a variety of other preservatives and skin penetration enhancers that may potentially increase the risk of an allergic reaction.  In fact, last weeks Label Poise product was a lotion that contains four different preservatives (methylparaben, phenoxyethanol, propylparaben, and methyisothiazolinone).  MIT has been shown to be neurotoxic in ‘in vitro’ tests of neurons in rat brain tissue cultures; similar studies using MCI showed that it was 30-100 times more effective of causing a neurotoxic response.  Methyisothiazolinone is also a known environmental toxin, particularly to fish, though the majority of incidences are cause by non-cosmetic uses.

CONCLUSIONS

Methyisothiazolinone and Methylchloroisothiazolinone are both known skin allergens and sensitizers that are used in approximately 23% of personal care products, though they typically are not found in products marketed as natural or organic.  Whether or not you choose to use products containing these preservatives is entirely up to user discretion. If you have used products containing MIT and MCI, and noticed a skin reaction you should discontinue use.  Otherwise, they should not be a significant cause of concern.

 

References

Boyapati, A., Tam, M., Tate, B., Lee, A., Palmer, A., and R. Nixon. 2013. “Allergic contact dermatitis to methylisothiazolinone: Exposure from baby wipes causing hand dermatitis.”  Australasian Journal of Dermatology. 54(4):254-267.

Castanedo-Tardana, M. and K. Zug.  2013.  Methylisothiazolinone.  Dermatitis.  24(1): 2-6.

Yazar, K., Johnsson, S., Lind, M., Boman, A., and C. Liden. 2010. “Preservatives and fragrance in selected consumer-available cosmetics and detergents.”  Contact Dermatitis.  64: 265-272.

Preservatives in Natural Products: Parabens

The primary focus of Nature’s Pulchritude is to educate.   This post is the first in a series of in depth posts that will educate you about the various preservatives in hair and skin products, as well as their potential toxicity.

PURPOSE

Preservatives are added to cosmetics, personal care products, and food to maintain a products integrity and stability by inhibiting or reducing the growth of microorganisms such as bacteria and fungus (FDA).  Most products sold via retail sit for extended periods of time during shipping, in a warehouse, and on store shelfs that allow enough time for a product to spoil or cause microbial growth which render the product unfit for use.  This is particularly true for products that contain water, such as many conditioners and moisturizers, and other active ingredients (antioxidants and emulsifiers) that would otherwise lose their effectiveness and stability over time.

Preservatives are chosen in cosmetics based on a variety of factors which include ability to inhibit growth over a broad spectrum and method of derivation (natural vs. synthetic).  Preservatives tend to be in concentrations less than 2% of the weight of the formula, however, widespread use of potentially harmful preservatives, such as parabens, has been a great cause of concern for some scientists and consumers.  The Food, Drug, and Cosmetic Act does not grant the Food & Drug Administration the authority to regulate the use of preservatives unless it is known to be “poisonous or deleterious” (FDA).

PARABENS

Parabens are cosmetic preservatives that are esters of p-hydroxybenzoic acid that have been widely used for decades due to their overall recognition as being safe up to concentrations of 25%, which is far more than what is typically used in individual products (FDA).  Specifically known as ethylparaben, methylparaben, propylparaben, benzylparaben, isobutylparaben, and butylparaben, these preservatives came to the forefront of controversy when parabens were discovered in breast tumors by researchers in 2004.  Parabens have been found to be oestrogenic and increase progesterone (pregnancy related hormone) receptor gene expression (Darbre et al. 2004; Harvey and Darbre 2004; Harvey and Everett 2004).  The primary concern about parabens is whether or not they have the ability to accumulate and linger in human tissues despite being used in concentrations of less than 1% from multiple sources of exposure (Darbre et al. 2004).

Chemical Structure of 7 Paraben Esters

Hazards & Safety

Studies in animals have shown that parabens are “rapidly, absorbed, metabolized, and excreted” (Darbre et al. 2004). Parabens can be absorbed through intact skin which may be the result of various penetration enhancers contained in cosmetics, though various characteristics of skin also influence absorption (Darbre et al. 2004). This can be problematic because parabens are lipophilic and therefore have a propensity to bind to fatty tissues as opposed to water (Darbre et al. 2004).  Parabens are weakly oestrogenic, and the side effects of long term exposure at low-levels to “synthetic xenoestrogens” is largely unknown (Harvey and Everett 2004).  The oestrogenic interactions of parabens have been observed in humans and animals in various capacities. In humans this is believed to have an impact on the “incidence and treatment” of breast tumors (Darbre et al. 2004).

17-β-Estradiol is a naturally occurring estrogen. Diethylstilboestrol is a synthetic estrogen.

This particular study, Concentrations of parabens in human breast tumors , only assessed tissues from breast tumors as opposed to breast tissues without tumors which may or may not impact how the toxicity of parabens is assessed. The study states that the results for parabens in breast tissues falls within the broad range of concentrations for polychlorinated biphenols (PCBs) and pesticide residues (Darbre et al. 2004). Darbre was not able to determine the source of the parabens, how they entered the body (oral or dermal), or how parabens accumulated in breast tissues (via transport in body or by being topically applied to target area) which makes a definite link to causality of cancerous cells difficult (2004). Methylparaben was found in 62% of total parabens recovered from human breast tissue, which may be attributed to its widespread use or higher ability to be absorbed by the body than other parabens (Darbre et al. 2004; Yazar et al. 2010). Additionally, parabens have been shown to cause a higher frequency of hypersensitivity than other preservatives (Tomar et al. 2005).

CONCLUSIONS

There is enough evidence to be skeptical about the use of parabens in cosmetics and subsequent impact on consumers.  This validates the exploration of other preservative options, however, it cannot be stated that parabens cause cancer.  Presence of parabens in breast tumors does not mean that parabens caused the tumors, nor that topical use from cosmetics was the source of parabens in the body.  It is important to note that the chemicals used in conjunction with parabens, such as penetration enhancers, also impact their absorption by the body.  More research needs to be done to throughly assess the health impacts of parabens, however, present information supports a decrease in their use in favor of less potentially toxic preservatives.

References:

Darbre, P., Aljarrah, A., Miller, R., Coldham, N., Sauer, M., and G. Pope.  2004.  “Concentrations of parabens in human breast tissue.”  Journal of Applied Toxicology.  24: 5-13.

Harvey, P. and P. Darbre.  2004.  “Endrocrine disrupters and human health: could oestrogenic chemicals in body care cosmetics adversely affect breast cancer incidence in women?”  Journal of Applied Toxicology.  24: 167-176.

Harvey, P. and D. Everett.  2004.  “Significance fo the detertion of esters of p-hydrooxybenzoic acid (parabens) in human breast tumors.”  Journal of Applied Toxicology.  24: 1-4.

Tomar, J., Jain, V., Aggarwal, K., Dayal, S., and S. Gupta.  2005. “Contact allergies to cosmetics: testing with 52 cosmetic ingredients and personal products.” Journal of Dermatology.  32: 951-955.

U.S. FDA.  2007.  Parabens.  FDA.gov.

Yazar, K., Johnsson, S., Lind, M., Boman, A., and C. Liden.  2010.  “Preservatives and fragrance in selected consumer-available cosmetics and detergents.”  Contact Dermatitis.  64: 265-272.

Preservatives in Natural Products

You may or may not have noticed that my posts for my series “The Globes” for February were scant–this was not intentional.  The vast majority of the product lines I was researching contained the same ingredient, which upon further research was a preservative listed under a trade name.  Initially, it seemed as if it was yet again another ‘hidden’ ingredient in “natural” hair products.  However, upon further research, though this particular preservative was most common, it was by no means the only one being used.  This extends into skin care as well.  Parabens have been the primary focus in addressing preservatives and chemicals in personal care products, however, their replacements may not be any better.  This is an example of why reading ingredient labels thoroughly, and having significant scientific basis for ‘condemning’ an ingredient is crucial.  Products that are sold commercially have to be preserved to assure their safety, therefore, cosmetic chemists replace parabens with something that can be equally as bad, unbeknownst to the average consumer who is assured by the label ‘paraben free,’ which does not mean preservative free.  The primary focus of Nature’s Pulchritude is to educate.  I want to make sure that you (and I) understand the impacts, if any, of any preservative in products on the market, whether marketed as natural organic or otherwise, before you purchase a product that contains them.  This post has been long in the making and is the precursor to a series of in depth posts that will educate you about the various preservatives in hair and skin products, as well as their potential toxicity.

Did you know that your products contained non paraben preservatives that can also impact your health?  What are some preservatives you know that are used in personal care products?