following is a summary of the latest safety analysis of butylene glycol:
Safety Assessments of Butylene Glycol
glycol (BG) (1,3-Butanediol, CAS No. 107-88-0) is a common humectant and
solubilizer used in cosmetic and food preparations. Its safety and usage has
been well documented and approved by such agencies as the US FDA, the US EPA,
and the CTFA (see below). Studies have even shown that when ingested by mammals,
BG metabolizes into b-hydroxybutyraldehyde which is then converted through a
process of intermediates into acetyl CoA, an intermediate of the citric acid
cycle, which supplies energy to the body in the form of ATP.
following statements come from the United States Environmental Protection Agency
High Production Volume Challenge Program Submission 2003: "Acute toxicity is
minimal by the oral and inhalation routes, and repeated-dose administration of
high doses to experimental animals and humans does not produce adverse effects
until the amount ingested becomes a significant contributor to the individualís
caloric requirement. Even then, the observed effects are limited to minor
reduction in body weight gainsÖresulting from the metabolism of 1,3-Butanediol
as a nutrient."1 The EPA reviewed this statement and found that "Adequate data
were provided for the acute, repeated-dose, and developmental toxicity endpoints
for the purposes of the HPV Challenge Program." The data of this study also
showed that BG had no multigenerational nor developmental toxicity. It also
showed that chronic studies did not show any carcinogenic activity.
The US FDA
has also verified the safety of BG even as an ingestible. The FDA approved BG as
a direct food additive as a flavor solubilizer. It has also been granted several
indirect additive approvals.
The use of
butylene glycol in cosmetics has been reviewed by the Cosmetic Ingredient Review
of the Cosmetic, Toiletry and Fragrance Association (CTFA). That report
concluded that BG was safe as presently used in cosmetics.
Federal Register, Vol. 62, No. 92, May 13, 1997; Part 172.
Ingredient Review. Final Report on the Safety Assessment of Butylene Glycol,
Hexylene Glycol, Ethoxydiglycol, and Dipropylene Glycol. J. Am. Coll. Toxicol.
is the safest of a class of chemicals called solubilizers
Glycolís have extremely wide variations in toxicity that match their many
applications in a variety of consumer products. Ethylene glycol is very well
known as automobile anti-freeze. It is toxic upon ingestion, causing direct
toxicity to erythrocytes [red blood cells]. Ethylene glycol is also teratogenic
and a possible bone marrow depressant. The very similar propylene glycol has
none of the same toxicity associated with ethylene glycol. In huge oral doses,
propylene glycol can cause liver and kidney toxicity... Propylene glycol is both
a skin irritant and a sensitizer.
glycol (1,4-butanediol) has none of the above toxicities. In fact there has been
no documented organ-specific toxicity associated with 1,3-butanediol. Butanediol
is also not a carcinogen.2 It is not a skin sensitizer, and is not considered a
skin irritant.1 In undiluted form butylene glycol may irritate the eye and
lining of the respiratory tract.
Consumer Advocates call butylene glycol an anti-freeze, and imply it is toxic
because of its characterization as a glycol. Just about anything added to water
is an anti-freeze. It is ludicrous then to label all anti-freeze formulations as
toxic. Glycolís can prevent water from freezing at 0 degrees Celsius. This fact
does not make all glycolís toxic, especially in the same manner and at the same
levels of toxicity. Butylene glycol is present in several Neways products.
concerns: Butylene glycol is rapidly absorbed through any tissue, including the
skin. It is rapidly metabolized to gamma-hydroxybutyric acid in animals and
humans. Gamma-hydroxybutyric acid is a naturally occurring chemical found in the
brain and peripheral tissues of humans. Gamma-hydroxybutyric acid is also
rapidly metabolized into succinate through the tricarboxylic acid cycle within
the body. Given in high doses, a neuromodulator effect can be seen.4 However, in
the small doses used as a solvent in pharmaceuticals and nutritionals, there are
no known side effects. In water-based products, a concentration of 0.5% butylene
glycol, as a solvent, would be safe for topical use.
profile: Butylene glycol in concentrations of 0.5% or less in a topically
applied product scores at least 9 out of 10, with a score of 10 being perfectly
Funk JO, et
al. Contact Dermatitis 1994;31:236-41. Propylene glycol dermatitis:
re-evaluation of an old problem.
National Toxicology Program, Toxicity Report Series no.54, NIH, US Dept of
Health and Human Services, NIH Publication #96-3932, 41 pages, 80 references.
Technical Data Sheet. 1997 Jan.
Publication #PB97-108161. 1996 May.
Anon. J Am Coll Toxicol
1985;4(5):223-48. Final report on the safety assessment of butylene glycol.
comparing small dialcohol (glycol) molecules, molecular weight makes a huge
difference in effect and toxicity. Butylene glycol is a better humectant (skin
moisturizer) and less toxic than propylene glycol. As an
alternative to the harmful ingredients propylene glycol, and ethylene glycol,These studies have come
from very conservative ingredient safety review groups such as the well
respected CTFA. In general, the CTFA seems to confirm Neways suspicions
regarding many other harmful ingredients. Nevertheless, butylene glycol is an
ingredient that has been confirmed to be safe as a topical ingredient and even
as an ingestible.
It has been examined by researchers and found to
be as safe as many other natural ingredients. It is not a