Montfort A. Johnsen
One might say that the air fresheners in use today began ignominiously as space
deodorants in subway stations and safe houses during the Nazi bombings of London
in 1943. Atomizers sprayed diluted hexylresorcinol into the air of these over-crowded
shelters to kill air-borne bacteria and protect the health of people
standing there for many hours.
Hexylresorcinol had been synthesized by Dohme, et al, in Germany during
1926, and a few years later it was recognized as an anthelmintic (used to destroy
parasitic worms) and topical antiseptic. By about 1935 it was pronounced to
be a space bactericide. When disposable aerosols became commercial in 1947,
hexylresorcinol was considered but probably not marketed since triethylene
glycol had been found to be at least eight times more effective in the killing of
airborne bacteria. It was also easily purified and less costly.
A few small firms marketed aerosol space bactericides in 1947. They had
to be approved by the U.S. Dept. of Agriculture (USDA), who administered
U.S. Patent #2,321,023 to Lyle
D. Goodhue and William N.
Sullivan. However, if the label
identified the product as a space
deodorant, federal registration
could be avoided. Survey data by
DuPont indicated that no room
deodorants were marketed in
1947, although probably a small
number were commercialized late that year. The
figure for 1948 was 2 million, and this grew to 3.5
million in 1949. By 1957, the market was 44 million,
according to DuPont.
The very early air deodorants contained formulas
with 2.5% to 7.0% triethylene glycol, although about
2.9% was sufficient to treat an average room. Other
glycols were sometimes included to about 3% but
(like propylene glycol) they were only about 10% as
effective as triethylene glycol. Glycols, being somewhat
polar, were generally insoluble in the hydrofluorocarbon (HFC) propellants. So a co-solvent,
such as ethanol or odorless mineral spirits (OMS), was needed.
Fragrances were added, almost as an afterthought, to give the consumer a feeling of accomplishment.
The propellant was about 85% of an equal mixture of non-flammable CFC-11 and CFC-12.
This provided a nice spray, with particles averaging about 12 microns in aerodynamic diameter;
they were small enough so they could hang in the air, evaporating most of their initial size over
a few minutes. This caused a pleasing intensification of the fragrance odor. Delivery rates were
generally about 0.75 grams per second (g/s). For a typical 6oz. (170g) fill, the dispenser could be
sprayed for about 3.9 minutes before becoming empty. A formulation would then be:
Early Air Deodorant (Circa 1949)
n 7.0% Triethylene Glycol (Air Treatment Grade)
n 0.2% Fragrance
n 7.8% Odorless Mineral Spirits (OMS)
n 42.5% CFC-11 (Trichloromonofluoromethane)
n 42.5% CFC-12 (Dichlorodifluoromethane)
As always, management and formulators were assiduously looking for ways to reduce product
cost. During 1955, a contract filler in Danville, IL found a way to purify isobutane, making it
Technical Editor
The Vicissitudes of
Aerosol Air Fresheners
24 Spray June 2020
1936 magazine advertisement for
Sharp & Dohme Hexylresorcinol
Dr. Lyle D. Goodhue (left) and William
N. Sullivan.