Came across this web site while doing research. Very informative for those who want to know more about PG.
From the propylene glycol website:
Propylene Glycol : All about propylene glycol
Safe use for over 50 years
The use and effects of propylene glycol have been thoroughly researched. It has been used safely for more than 50 years, including adoption in health-sensitive applications such as food, cosmetics and pharmaceuticals, where the molecule mainly serves as non-active ingredient or carrier of other substances.
Studies have proven that propylene glycol has a very low degree of toxicity. In the body, propylene glycol is rapidly converted into lactic acid, in a similar manner to what happens with with sugar (energy) in the muscles during sports.
For the environment, studies have shown that propylene glycol is neither persistent nor does it bio-accumulate - it is readily biodegradable.
Accordingly, there is
A multi-talent
With its unique combination of properties propylene glycol fulfils various roles in different environments. It
By emulsifying the active ingredients, which otherwise would not mix, the propylene glycol creates a stable homogeneous fluid that will allow the intended final product, be it a face cream or shampoo, for example, to do its job.
Markets:
Enabling every day convenience
Propylene glycol enables a large variety of consumer and industrial applications: In food and beverage, feed, cosmetics and pharmaceutical applications, propylene glycol USP/EP (pharmaceutical grade) is used, for example, to dissolve flavouring in drinks, to keep animal feed moist, to homogeneously emulsify oily and watery elements in creams, sprays and liquids, or as solvent (excipient) for the active ingredients in medicines.
Regulatory:
Authorities confirm safety of propylene glycol
Several international authorities investigated the safety of propylene glycol. Both the Organisation for Economic Cooperation and Development (OECD), and the Canadian Centre for Occupational Health and Safety, have published risk assessments that indicate the very low toxicity of propylene glycol.
If propylene glycol is used in pharmaceuticals applications, strict specifications for quality as laid out in the European Pharmacopoeia, have to be followed. The latest edition of this official document of the European Directorate for the Quality of Medicines (EDQM) was published in 2008; it is used in more than 37 countries in Europe. In the US, propylene glycol is listed as GRAS – Generally Recognized as Safe – for use in food and pharmaceuticals in the US-Pharmacopoeia (Ref21CFR), the official FDA (US Food & Drug Administration) document.
The European authorities responsible for consumer health have approved the use of propylene glycol with food:
A well understood substance
Chemically, propylene glycol has a very simple structure:
The two parts of the molecule, the alcohol groups ("OH", likes water) and the hydrocarbon backbone ("CH", likes oil), represent fundamental chemical characteristics. Their behaviour both in industrial processes, as well as in the human body or in the environment, is well understood.
In the human body, propylene glycol is quickly metabolised and excreted. Its metabolic pathway is comparable to that of sugar: propylene glycol is rapidly converted into lactic acid, in a similar manner to what happens with sugar (energy) in the muscles during sports. It is the lactic acid in your muscles which makes them ache following intensive exercise. Lactic acid, the metabolite of propylene glycol, therefore, is also naturally present in our bodies. It is excreted via urine.
In the environment, tests have shown that propylene glycol is readily biodegradable.
Studies show that propylene glycol has a very low degree of toxicity. From a toxicological point of view, alcohol is more toxic than the same amount of propylene glycol.
Taste, fun and convenience
Propylene glycol USP/EP (pharmaceutical grade) is the ideal carrier of a large variety of flavours that give most of today's food and beverage their distinctive taste: The substance itself is colour-, taste- and odourless, and it does not react on its own, which means that it can perform its function without impacting on other product attributes. It has been confirmed as safe and hygienic, and provides unique inherent properties with regard to holding/attracting both water- and oil-based substances. In food it is used to retain food colour pigments and distribute them evenly within the mixture.
Propylene glycol USP/EP (pharmaceutical grade) has been approved for use as a food additive under the E-number E 1520. In direct food contact it is mainly used as
Pharmaceuticals:
Safety and reliability for health and therapy
The most direct way of applying a substance to the human body is injection into the blood or the tissue, closely followed by ingestion or inhalation. Making the curing agent reliably available to the organism is key to the efficiency of any pharmaceutical application. Propylene glycol USP/EP (pharmaceutical grade) is qualified and approved for this use as laid down in the respective Pharmacopoeia (USA, EU, Japan etc.). The main function of propylene glycol USP/EP (pharmaceutical grade) in pharmaceuticals is to solubilise and provide equal distribution of the active ingredient in the formulation, so that each pill, liquid dose or cream-based application always contains the exactly prescribed amount of curing agent:
Pharmaceutical applications include…
All liquid household and dishwashing detergents, as well as industrial soaps and cleaning fluids, require a homogeneous distribution of the active cleaning ingredient within the liquid. Propylene glycol acts as a stabiliser for the dirt-removing ingredients, and, at the same time, helps them to retain their function even at lower temperatures. Thus, cleaning liquids remain crystal-clear at normal use temperatures. Propylene glycol is a safe and efficient enabling agent in these applications.
From the propylene glycol website:
Propylene Glycol : All about propylene glycol
Safe use for over 50 years
The use and effects of propylene glycol have been thoroughly researched. It has been used safely for more than 50 years, including adoption in health-sensitive applications such as food, cosmetics and pharmaceuticals, where the molecule mainly serves as non-active ingredient or carrier of other substances.
Studies have proven that propylene glycol has a very low degree of toxicity. In the body, propylene glycol is rapidly converted into lactic acid, in a similar manner to what happens with with sugar (energy) in the muscles during sports.
For the environment, studies have shown that propylene glycol is neither persistent nor does it bio-accumulate - it is readily biodegradable.
Accordingly, there is
- <LI class=copy_bullets>no official hazard classification or labelling of propylene glycol, and
- propylene glycol is not listed "negatively" in any country of the EU
A multi-talent
With its unique combination of properties propylene glycol fulfils various roles in different environments. It
- <LI class=copy_bullets>serves as a solvent <LI class=copy_bullets>connects and stabilises insoluble fluids (emulsifier) <LI class=copy_bullets>helps to bind and transport other substances (excipient) <LI class=copy_bullets>holds and dissolves active ingredients equally in a medium <LI class=copy_bullets>attracts/holds water/moisture (hygroscopic) <LI class=copy_bullets>reduces the freezing point <LI class=copy_bullets>increases the boiling point
- offers outstanding stability with high flash and boiling points
By emulsifying the active ingredients, which otherwise would not mix, the propylene glycol creates a stable homogeneous fluid that will allow the intended final product, be it a face cream or shampoo, for example, to do its job.
Markets:
Enabling every day convenience
Propylene glycol enables a large variety of consumer and industrial applications: In food and beverage, feed, cosmetics and pharmaceutical applications, propylene glycol USP/EP (pharmaceutical grade) is used, for example, to dissolve flavouring in drinks, to keep animal feed moist, to homogeneously emulsify oily and watery elements in creams, sprays and liquids, or as solvent (excipient) for the active ingredients in medicines.
Regulatory:
Authorities confirm safety of propylene glycol
Several international authorities investigated the safety of propylene glycol. Both the Organisation for Economic Cooperation and Development (OECD), and the Canadian Centre for Occupational Health and Safety, have published risk assessments that indicate the very low toxicity of propylene glycol.
If propylene glycol is used in pharmaceuticals applications, strict specifications for quality as laid out in the European Pharmacopoeia, have to be followed. The latest edition of this official document of the European Directorate for the Quality of Medicines (EDQM) was published in 2008; it is used in more than 37 countries in Europe. In the US, propylene glycol is listed as GRAS – Generally Recognized as Safe – for use in food and pharmaceuticals in the US-Pharmacopoeia (Ref21CFR), the official FDA (US Food & Drug Administration) document.
The European authorities responsible for consumer health have approved the use of propylene glycol with food:
- <LI class=copy_bullets>in direct food contact (Link: Dir95/2/EC and amendments) as food additive E1520;
- in indirect food contact (Link: Dir2002/72/EC and amendments) relating to plastic materials and articles intended to come into contact,
A well understood substance
The two parts of the molecule, the alcohol groups ("OH", likes water) and the hydrocarbon backbone ("CH", likes oil), represent fundamental chemical characteristics. Their behaviour both in industrial processes, as well as in the human body or in the environment, is well understood.
In the human body, propylene glycol is quickly metabolised and excreted. Its metabolic pathway is comparable to that of sugar: propylene glycol is rapidly converted into lactic acid, in a similar manner to what happens with sugar (energy) in the muscles during sports. It is the lactic acid in your muscles which makes them ache following intensive exercise. Lactic acid, the metabolite of propylene glycol, therefore, is also naturally present in our bodies. It is excreted via urine.
In the environment, tests have shown that propylene glycol is readily biodegradable.
Studies show that propylene glycol has a very low degree of toxicity. From a toxicological point of view, alcohol is more toxic than the same amount of propylene glycol.
Taste, fun and convenience
Propylene glycol USP/EP (pharmaceutical grade) is the ideal carrier of a large variety of flavours that give most of today's food and beverage their distinctive taste: The substance itself is colour-, taste- and odourless, and it does not react on its own, which means that it can perform its function without impacting on other product attributes. It has been confirmed as safe and hygienic, and provides unique inherent properties with regard to holding/attracting both water- and oil-based substances. In food it is used to retain food colour pigments and distribute them evenly within the mixture.
Propylene glycol USP/EP (pharmaceutical grade) has been approved for use as a food additive under the E-number E 1520. In direct food contact it is mainly used as
- <LI class=copy_bullets_pharma>solvent and carrier of flavour or colour in the food and beverage manufacturing processes, to make drinks, biscuits, cakes, sweets
- thickener, clarifier and stabiliser in food and beverage such as beer, salad dressings or baking mixtures
Pharmaceuticals:
Safety and reliability for health and therapy
The most direct way of applying a substance to the human body is injection into the blood or the tissue, closely followed by ingestion or inhalation. Making the curing agent reliably available to the organism is key to the efficiency of any pharmaceutical application. Propylene glycol USP/EP (pharmaceutical grade) is qualified and approved for this use as laid down in the respective Pharmacopoeia (USA, EU, Japan etc.). The main function of propylene glycol USP/EP (pharmaceutical grade) in pharmaceuticals is to solubilise and provide equal distribution of the active ingredient in the formulation, so that each pill, liquid dose or cream-based application always contains the exactly prescribed amount of curing agent:
Pharmaceutical applications include…
- <LI class=copy_bullets_pharma>therapeutic drugs and medicines, such as vaccines or cough syrup <LI class=copy_bullets_pharma>local anaesthetics <LI class=copy_bullets_pharma>antiseptics
- vitamins and hormones
Liquid detergents:
Reliable use – safe for humans All liquid household and dishwashing detergents, as well as industrial soaps and cleaning fluids, require a homogeneous distribution of the active cleaning ingredient within the liquid. Propylene glycol acts as a stabiliser for the dirt-removing ingredients, and, at the same time, helps them to retain their function even at lower temperatures. Thus, cleaning liquids remain crystal-clear at normal use temperatures. Propylene glycol is a safe and efficient enabling agent in these applications.
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