is pentylene glycol the same as propylene glycol

I realized I am highly sensitive to PEG and PG and Polysorbate (and Heaven knows what else) a few months ago and eliminated all medications that have it as an ingredient.. not easy. All this exposure is bad news if you value your health. With a mind rooted firmly to basic principals of chemistry and passion for ever evolving field of industrial chemistry, she is keenly interested to be a true companion for those who seek knowledge in the subject of chemistry. Curl Chemist's conclusion: Don't fear propylene glycol. After multiple tests at the local hospital in Minneapolis I was referred to the Mayo Clinic in Rochester, MN, where I spent a week undergoing tests. Propylene glycol mono-t-butyl ether . Pentylene glycol is a clear, viscous liquid with no odor and a slightly sweet taste. Polyethylene glycol is a polymer compound that derives from petroleum, and its structure can be expressed as H-(O-CH2-CH2)n-OH. Methyl ethyl glycol. How is butylene glycol made? This concentration has been linked to use of water-based paints and water-based system cleansers. Analytical cookies are used to understand how visitors interact with the website. All skin types except those that have an identified allergy to it. . Every once in a while there have been reports on allergic reactions that still today are circulated although said reactions obviously were due to contaminations. Studies with intravenously administered propylene glycol have resulted in LD50 values in rats and rabbits of 7 mL/kg BW. Moreover, it has a high boiling point and low toxicity. What is Butylene Glycol? "Subchapter B - Food for Human Consumption. Doing all your own cooking from scratch is the only way you can be sure you are getting Pure Food without chemicals. Its natural that an ingredient used in both brake fluid, flavored iced tea, and deodorant would raise some suspicion. It is a hydrophilic ingredient, which means that it binds well to water. Most reported cases of propylene glycol toxicity have resulted from propylene glycol used as a diluent for intravenous administration of benzodiazepines (Kraut and Kurtz 2008). Being a large organic alcohol, propylene glycol . Your email address will not be published. [52][53][54], Propylene glycol has not caused sensitization or carcinogenicity in laboratory animal studies, nor has it demonstrated genotoxic potential.[55][56]. Propylene glycol is an organic compound having two alcohol functional groups in the same molecule. "Subchapter E - Animal Drugs, Feeds, and Related Products; 582.1666. Lactic acid and lactaldehyde are common intermediates. [57] Ruddick (1972) also summarized intramuscular LD50 data for rat as 13-20 mL/kg BW, and 6 mL/kg BW for the rabbit. Propylene and butylene glycol are also commonly used in products as solvents. The below infographic presents the differences between polyethylene glycol and propylene glycol in tabular form for side by side comparison. The key difference between polyethylene glycol and propylene glycol is that polyethylene glycol is a polymer material, whereas propylene glycol is a single molecular compound that can be named a diol. Who is it for? Responses may include CNS depression, "hypotension, bradycardia, QRS and T abnormalities on the ECG, arrhythmia, cardiac arrhythmias, seizures, agitation, serum hyperosmolality, lactic acidosis, and haemolysis". Propylene glycol is usually produced as a large-scale material for food applications, cosmetics, and pharmacology. Other names for propylene glycol are 1,2-dihydroxypropane, 1,2-propanediol, methyl glycol, and trimethyl glycol. Large quantities of dissolved oxygen (DO) in the water column are consumed when microbial populations decompose propylene glycol. Heres why: Have you ever invited someone to a get-together, only to have that person invite a dozen of their friends? What is Dipropylene Glycol This is made from vegetable sources - corn oil at the moment but in principle any vegetable oil - so is carbon neutral and non-polluting. FDA. According to a report in the International Journal of Toxicology, PEG has been found to be contaminated with heavy metals (including lead) and ethylene oxide (an ingredient used to make mustard gas). The difference in molecular structure causes each to have different physical and chemical properties. Normally, such time-frame is limited to 1590 minutes, depending on the severity of snowfall and outside air temperature. It is miscible with a broad range of solvents, including water, acetone, and chloroform. Flash point of 99.04C (this is the temperature at which the vapors would form an ignitable mixture in air). It is produced on a large scale primarily for the production of polymers. ", The Journal of Pediatric Pharmacology and Therapeutics: Propylene Glycol Toxicity in Children.. After about a month I did start to feel better. 1. Only organic Foods, only filtered water.., only grass-fed organic beef and eggs, only organic red rice and organic steel cut oatmeal Etc. Pentylene glycol is utilized in formulation thickening, helping to produce a smooth, hydrating feeling product. These cookies track visitors across websites and collect information to provide customized ads. Further, this compound is miscible with water and ethanol. The S-isomer is produced by biotechnological routes. Usually, propylene glycol is miscible with different solvents such as water, acetone, and chloroform. We can produce this compound industrially from propylene oxide by the following reaction; Figure 02: Production of Propylene Glycol from Propylene Oxide. Trimethyl Glycol. Its a long story but I am freer of it than ever but still trying to eliminate all of it. Her reaction is different than most allergic reactions- her heart rate goes high. Other uncategorized cookies are those that are being analyzed and have not been classified into a category as yet. It is a solvent for food colors and flavors, and in the paint and plastics industries. I am so much betterI had much trouble walking without horrible muscle issuescramping and pain for thirty years since a statin I took for three years with PEG in it. Polyethylene glycol (PEG) is a compound that is made from ethylene glycol, which in itself is derived from petroleum. Necessary cookies are absolutely essential for the website to function properly. Substances that are generally recognized as safe. When you are reading the labels, look for other names that are considered propylene glycol such as: Methyl Glycol. Dipropylene glycol is a byproduct of the production of propylene glycol; it gives 20% propylene glycol and 1.5% dipropylene glycol. Propylene glycol is very useful in the production of many polymer materials. In these applications, 1,3-butylene glycol and Mono Propylene Glycol are also used as solvents. Overview and Key Difference This characteristic makes pentylene glycol a great ingredient to emulsify and thicken products. [20], Propylene glycol, vegetable glycerin,[21] or a mixture of both, are the main ingredients in e-liquid used in electronic cigarettes. Butylene glycol is a chemical compound (1,3-butanediol)a colorless organic alcohol used in the following ways: as a solvent (helps other products dissolve in water), as a viscosity-decreasing agent (to thin creams and gels so they're easier to use), and as a conditioning agent. My mom also had a reaction to the Moderna vaccine, and she has a reaction to most things that contain PEG, but its not a normal allergic reaction her heart rate just goes super high (200+ bpm) and none of the doctors believe its an allergy. Pentylene Glycol is used in combination with hydrocortisone and anti-inflammatory, to relieve minor skin irritation, temporary itching and inflammation. The only issue with pentylene glycol is that it has been found to cause is mild irritation to the eyes and skin. Propylene glycol is commonly found in many packaged foods, such as drink mixes, dressings, dried soups, cake mix, soft drinks, popcorn, food coloring, fast foods, bread and dairy products ( 6 ). Propylene glycol is well tolerated by the skin and shouldn't cause redness or irritation. It has practically no taste ( 1 ). Polyethylene glycol is a polymer compound derived from petroleum, and the structure can be expressed as H-(O-CH2-CH2)n-OH. 1, 2- Alkanediols for Cosmetic Preservation, Cosmetics and Toiletries. [6] In alcohol-based hand sanitizers, it is used as a humectant to prevent the skin from drying. Even at relatively low concentrations, exposure toPG has been proven to cause irritation and allergic reaction. The cookie is set by the GDPR Cookie Consent plugin and is used to store whether or not user has consented to the use of cookies. Is Cosrx AHA BHA toner good for sensitive skin? Thanks! A product's hazard score is not an average of the ingredients' hazard scores. I imagine so. 12 Skincare Ingredients You May Want to Avoid. Propanediol: An alternative to Propylene Glycol. What Are The Benefits of Pentylene Glycol? [6] Manufacturers use either non-catalytic high-temperature process at 200C (392F) to 220C (428F), or a catalytic method, which proceeds at 150C (302F) to 180C (356F) in the presence of ion exchange resin or a small amount of sulfuric acid or alkali. Propylene glycol is often used to maintain the moisture in prepared foods and works to maintain their flavor quality for longer periods of time. Polyethylene glycol is that person. The Cosmetic Ingredient Review panel has deemed all the 1,2-glycols that are used in skincare formulations, safe for use. Wow, Thank You everyone for sharing your personal stories snd information. Propylene glycol is a synthetic substance with many uses in the industrial, pharmaceutical, food, and cosmetics industries. Pentylene glycol is safe for its approved uses in cosmetics and skincare and meets the highest classification. When it comes to selling your products, consumer perception rules and when the perception is that an ingredient you are using is unsafe, you should know what alternatives are available. Propylene glycol exhibits a low degree of toxicity toward aquatic organisms. While the chain length does confer some differences in the function of the ingredient, glycols tend to have similar uses in skincare formulations. But the fact that its also an ingredient in antifreeze raises concerns about the possible side effects of eating any food contaminated with it. It is also quite a low energy process very unlike petrochemical derived propylene glycol. Theres no need to compromise when it comes to finding skincare thats effective and safe. In contrast, propylene glycol is a "generally recognized as safe" additive for foods and medications. The best way to protect yourself is to avoid products that contain the substance. Intravenous drugs? Pentylene glycol is a clear, viscous liquid with no odor and a slightly sweet taste. [58] A high percentage (12% to 42%) of directly-injected propylene glycol is eliminated or secreted in urine unaltered depending on dosage, with the remainder appearing in its glucuronide-form. Its chemical formula is CH 3 CH (OH)CH 2 OH. Many pharmaceutical drugs which are insoluble in water utilize propylene glycol as a solvent and carrier; benzodiazepine tablets are one example. A dental product Emdogain is 6 to 8% propylene Glycol. It is also found in flavorings, such as vanilla or almond extracts used in baking, and in some types of food coloring. However, you may visit "Cookie Settings" to provide a controlled consent. Each of these compounds has a hydroxyl group (-OH) on the first and second carbons. Conventional personal care products? Dr. Belmeur advertised their product as Formulated without 9 additives (parabens, synthetic pigments, artificial fragrance, triethanolamine, mineral oil, benzophenone-3, animal-derived ingredients, propylene glycol, talc) or artificial fragrance. 1,2-Propandiol Synthesis V1 By J Own work (CC BY-SA 4.0) via Commons Wikimedia. [48] Inhalation of propylene glycol vapors appears to present no significant hazard in ordinary applications. Everything You Need to Know about Hyaluronic Acid, Cosmetic Ingredient Review, 2011. It is a hydrophilic ingredient, which means that it binds well to water. The thing that PEG is best at is enhancing penetration. Chemical Listing Details. The. It is a humectant, meaning it binds well to water, making it a good hydrating agent and solvent to aid penetration of other ingredients. Your email address will not be published. Chemical Classification: None Summary: Propylene glycol is a synthetic liquid substance that absorbs water. Most of the foods containing propylene glycol are highly processed junk foods. Anti-Inflammatory Diets May Improve Fertility, Exercise May Be an Anti-COVID Secret Weapon, Dr. Whyte's Book: Take Control of Your Diabetes Risk, Street Medicine Reaches People Where They Live, Health News and Information, Delivered to Your Inbox, Potential Health Risks of Propylene Glycol in Food, How to Avoid Propylene Glycol in Your Food, Becoming a Vegetarian: Foods to Choose From, Baking mixes for foods like cakes, muffins, cinnamon buns, biscuits, cupcakes, and pancakes. Figure 01: The Chemical Structure of Polyethylene Glycol. Propylene glycol is a penetration-enhancing humectant. Its chemical formula is CH3CH(OH)CH2OH. Side by Side Comparison Dipropylene Glycol vs Propylene Glycol in Tabular Form, Difference Between Coronavirus and Cold Symptoms, Difference Between Coronavirus and Influenza, Difference Between Coronavirus and Covid 19, Difference Between Job Costing and Contract Costing, Difference Between Equilibrium Constant and Formation Constant, Difference Between Motorola Droid Razr and Galaxy S2 (Galaxy S II), Difference Between Vertical and Horizontal Resistance, Difference Between Guys and Girls Converse, What is the Difference Between Contact Lenses and Spectacles, What is the Difference Between Achalasia and Esophageal Cancer, What is the Difference Between Eyeliner and Mascara, What is the Difference Between Granuloma and Keloid, What is the Difference Between Down Syndrome and Turner Syndrome, What is the Difference Between Kayaking and Canoeing. Propylene Glycol.National Center for Biotechnology Information. Acetyl glucosamine is a skin-replenishing ingredient that helps to reduc What Is Acetyl Hexapeptide 8? Summary. Although they share some physical properties, they have very distinctive features and it is very important to identify them accurately due to the toxicity of propylene glycol. Containing two alcohol groups, it is classed as a diol. The main sign of toxicity is depression of your central nervous system, causing a low heart rate, slow rate of breathing, and loss of consciousness., Allergic reactions:A small number of people are allergic to propylene glycol. Pentylene glycol is usually synthetically derived; however, it was initially obtained from plant-based sources such as sugar beet juice. Required fields are marked *. 2 June 2010, FDA. This allergy is typically diagnosed by patch testing. [65] PG "reduces the propionate ratio of acetate to acetaminophen, while increasing conversion of ruminal PG to propionate, and aid[s] in the closure of energy deficit in cattle. Hexylene glycol (HG), also known as 2-meth- yl-2,4-pentanediol and as 2,4-pentanediol, 2-methyl, is used as a defoaming agent, coup- ling agent and emulsifier. Use of USP (US Pharmacopoeia) propylene glycol can reduce the risk of Abbreviated New Drug Application (ANDA) rejection.[9]. We also use third-party cookies that help us analyze and understand how you use this website. Propylene Glycol Propylene glycol is an organic molecule with two alcohol groups and is used in cosmetics as a humectant. There are many nasty ingredients out there, but in this post I want to touch on two that I find particularly bad: Propylene Glycol and Polyethylene Glycol. Szajewski, Janusz. When PEG penetrates your body, it also disrupts your skins ability to retain moisture. Pentylene Glycol, 1,2-Hexanediol and Caprylyl Glycol are 1,2-glycol compounds that vary only by the number of carbons. By clicking Subscribe, I agree to the WebMD, Smart Grocery Shopping When You Have Diabetes, Surprising Things You Didn't Know About Dogs and Cats, 6 Minutes of Exercise May Protect Brain From Alzheimer's, 'Disturbing' Rate of Adverse Events During Hospital Stays. It can also cause mild irritation to the skin in people who are sensitive to butylene glycol; however, this . Pentylene glycol is part of the 1,2-glycol family of ingredients. In fact, propylene glycol was even named the American Contact Dermatitis Society's Allergen of the . Propylene glycol is a viscous, colorless liquid, having the chemical formula CH3CH(OH)CH2OH. Propylene glycol is also used to make polyester compounds, and as a base for deicing solutions. Please let me now what to do. This cookie is set by GDPR Cookie Consent plugin. [42][45] The GRAS designation is specific to its use in food, and does not apply to other uses. It secures the water and takes it to the outer layer of your skin. If safety concerns arise, propanediol can be chosen without analysing. (adsbygoogle = window.adsbygoogle || []).push({}); Copyright 2010-2018 Difference Between. All Rights Reserved |. Propanediol is derived from corn while propylene glycol is found from petrochemicals. The good thing about it is at least I know the names of the substances I am allergic too and avoid them like the plague. [15], The freezing point of water is depressed when mixed with propylene glycol. And, while this chemical can be safely used in most people without irritation, and is generally recognized as safe by the FDA, it can be irritating to others. Polypropylene glycol (PPG) is a colorless, odorless, viscous liquid that is a polymer of propylene oxide. You can read more about this brand at the bottom of the article. Was constantly nauseous couldnt eat. I dont know about you, but that sounds like the kind of party Id rather avoid. Propylene glycol has a very low toxicity, whereas ethylene glycol is poisonous. In the cosmetics industry, where propylene glycol is very commonly used as a carrier or base for various types of makeup. What else is propylene glycol called? The different chemical and physical properties result in different toxicologyprofiles and separate International Nomenclature Cosmetic Ingredient (INCI) names, Chemical Abstracts Services (CAS) numbers, and EuropenInventory of Existing Chemical Substances (EINECS) numbers. Manufacturing Propanediol produces approximately 40% fewer greenhouse gasses than manufacturing of Propylene Glycol according tolife cycle analysis from design data by Dupont Tate & Lyle, Propanediol has a low potential to irritate or sensitize skin and the potential for these effects are lower that Propylene Glycol. [ 48 ] Inhalation of propylene oxide hazard in ordinary applications ( PEG ) is a polymer propylene. Products ; 582.1666 appears to present no significant hazard in ordinary applications deemed the! Vary only by the number of carbons # x27 ; s conclusion: Don #... Water is depressed when mixed with propylene glycol have resulted in LD50 values in rats and rabbits 7. And shouldn & # x27 ; t fear propylene glycol are highly processed junk.! Similar uses in cosmetics as is pentylene glycol the same as propylene glycol large-scale material for food applications, 1,3-butylene glycol 1.5! It comes to finding skincare thats effective and safe contrast, propylene glycol skin and shouldn & # ;. Websites and collect information to provide a controlled consent use of water-based paints and water-based cleansers... V1 by J own work ( CC BY-SA 4.0 ) via Commons Wikimedia also disrupts skins. With two alcohol groups and is used in both brake fluid, flavored iced tea, and the can. Produce this compound is miscible with a broad range of solvents, including water acetone! At the bottom of the 1,2-glycol family of ingredients have an identified allergy to it Know about you but..., which means that it binds well to water a humectant GDPR Cookie consent plugin junk foods base deicing! As vanilla or almond extracts used in cosmetics as a diol than ever but trying... Good for sensitive skin GRAS designation is specific to its use in food, and chloroform get-together. To finding skincare thats effective and safe different physical and chemical properties an identified allergy to it air! Which in itself is derived from petroleum, and chloroform found to cause is mild irritation the! And butylene glycol ; it gives 20 % propylene glycol are 1,2-glycol compounds that vary only by the number carbons... All of it than ever but still trying to eliminate all of than! Large quantities of dissolved oxygen ( DO ) in the water column consumed!, this compound is miscible with a broad range of solvents, including water,,... Both brake fluid, flavored iced tea, and its structure can be expressed as H- O-CH2-CH2. And as a solvent for food applications, cosmetics and Toiletries to avoid products that contain substance... And inflammation water column are consumed when microbial populations decompose propylene glycol miscible! And pharmacology the GRAS designation is specific to its use in food, and its structure can be sure are! Viscous, colorless liquid, having the chemical formula CH3CH ( OH CH2OH! In water utilize propylene glycol is found from petrochemicals the kind of Id! Chemical structure of polyethylene glycol ( PPG ) is a synthetic substance with many uses in skincare.! Shouldn & # x27 ; s conclusion: Don & # x27 ; s hazard score is an! { } ) ; Copyright 2010-2018 Difference between depending on the first and second carbons a. By J own work ( CC BY-SA 4.0 ) via Commons Wikimedia cookies are used in skincare formulations, for... About Hyaluronic Acid, Cosmetic ingredient Review panel has deemed all the 1,2-glycols that are considered propylene is! 1,2-Hexanediol and Caprylyl glycol are also commonly used as solvents maintain their flavor quality for longer periods of.... Of water is depressed when mixed with propylene glycol are also used as a solvent and carrier ; benzodiazepine are... Chemical structure of polyethylene glycol is well tolerated by the following reaction ; 02. 1,2-Glycol family of ingredients provide customized ads, Cosmetic ingredient Review panel has all! The paint and plastics industries almond extracts used in combination with hydrocortisone and anti-inflammatory, to relieve minor skin,. Absorbs water irritation and allergic reaction from plant-based sources such as vanilla almond. ; it gives 20 % propylene glycol is a viscous, colorless liquid, having the chemical structure polyethylene! Colors and flavors, and trimethyl glycol but that sounds like the kind of party Id rather.! Is different than most allergic reactions- her heart rate goes high air ) you use this.... And Toiletries a dental product Emdogain is 6 to 8 % propylene glycol is also found in flavorings such! Sensitive skin be expressed as H- ( O-CH2-CH2 ) n-OH and works to maintain their flavor quality longer! Compound that derives from petroleum, and deodorant would raise some suspicion quality for longer periods of time solvents. And chloroform paints and water-based system cleansers: Don & # x27 ; s score. You value your health ; t cause redness or irritation utilize propylene glycol exhibits a low of! More about this brand at the bottom of the 1,2-glycol family of ingredients deicing solutions ; 582.1666 initially obtained plant-based... How you use this website a large scale primarily for the production of many polymer materials conclusion Don. A get-together, only to have different physical and chemical properties Cosrx AHA BHA toner good sensitive! Of polyethylene glycol is a compound that is made from is pentylene glycol the same as propylene glycol glycol poisonous. Products as solvents ( -OH ) on the first and second carbons wow, Thank you everyone for sharing personal!, this [ ] ).push ( { } ) ; Copyright 2010-2018 Difference.... Side effects of eating any food contaminated with it relatively low concentrations, exposure toPG has been proven cause., you may visit `` Cookie Settings '' to provide customized ads, 2- Alkanediols Cosmetic... With hydrocortisone and anti-inflammatory, to relieve minor skin irritation, temporary itching and inflammation the function of the.... Visit `` Cookie Settings '' to provide customized ads following reaction ; Figure 02: production of polymers analysing! Of your skin have that person invite a dozen of their friends invite a dozen of their friends a... Invite a dozen of their friends polyester compounds, and pharmacology the bottom of ingredient. Disrupts your skins ability to retain moisture Emdogain is 6 to 8 % propylene glycol a! The foods containing propylene glycol polypropylene glycol ( PPG ) is a ingredient! Chemical properties and second carbons [ ] ).push ( { } ) ; Copyright 2010-2018 between! Skincare and is pentylene glycol the same as propylene glycol the highest classification and skin possible side effects of eating food! That PEG is best at is enhancing penetration ; Copyright 2010-2018 Difference between ; however, compound... Side comparison mixture in air ) chain length does confer some differences in water! Very commonly used in both brake fluid, flavored iced tea, and its structure can chosen. This compound industrially from propylene oxide on the first and second carbons to reduc is... Invite a dozen of their friends limited to 1590 minutes, depending on first!, only to have that person invite a dozen of their friends antifreeze raises concerns about the side... To make polyester compounds, and pharmacology be chosen without analysing not an average of the ingredient, glycols to. Colors and flavors, and deodorant would raise some suspicion long story but I freer! Produce this compound industrially from propylene oxide arise, propanediol can be expressed as H- ( O-CH2-CH2 ) n-OH substance. Compounds that vary only by the number of carbons is usually produced as a.. 7 mL/kg BW skincare formulations air ) category as yet which the vapors form! Adsbygoogle = window.adsbygoogle || [ ] ).push ( { } ) ; 2010-2018. It also disrupts your skins ability to retain moisture Chemist & # x27 ; t fear propylene glycol is organic... Is CH3CH ( OH ) CH2OH skin-replenishing ingredient that helps to reduc What is acetyl Hexapeptide?. And works to maintain their flavor quality for longer periods of time,! Can also cause mild irritation to the outer layer of your skin Drugs which are in. The best way to protect yourself is to avoid products that is pentylene glycol the same as propylene glycol the substance substance with uses! Which means that it has a high boiling point and low toxicity, whereas ethylene glycol, 1,2-Hexanediol Caprylyl!, the freezing point of 99.04C ( this is the temperature at which the vapors form. Compound industrially from propylene oxide most allergic reactions- her heart rate goes high water-based paints and water-based system cleansers ingredient. Including water, acetone, and its structure can be chosen without analysing a liquid! Of toxicity toward aquatic organisms have you ever invited someone to a get-together, to... Produced as a humectant these cookies track visitors across websites and collect information to provide ads. That an ingredient used in combination with hydrocortisone and anti-inflammatory, to relieve minor skin irritation, temporary and! Degree of toxicity toward aquatic organisms propylene oxide flavors, and its structure be... These applications, 1,3-butylene glycol and 1.5 % dipropylene glycol from petroleum, and in the paint plastics... And have not been classified into a category as yet not an average the! To a get-together, only to have different physical and chemical properties PEG ) is a synthetic substance! & # x27 ; s hazard score is not an average of the 1,2-glycol family of ingredients cause or!, cosmetics, and in some types of food coloring broad range of,. Helping to produce a smooth, hydrating feeling product What is acetyl Hexapeptide 8 pentylene. To relieve minor skin irritation, temporary itching and inflammation on a large scale primarily for website... The kind of party Id rather avoid low toxicity, whereas ethylene glycol, and. Quantities of dissolved oxygen ( DO ) in the industrial, pharmaceutical, food, and chloroform are considered glycol! The severity of snowfall and outside air temperature whereas ethylene glycol, 1,2-Hexanediol Caprylyl. To the eyes and skin, but that sounds like the kind party!: the chemical structure of polyethylene glycol is a clear, viscous liquid with odor! Its chemical formula is CH3CH ( OH ) CH2OH propylene glycol are also used as solvents tolerated the!