Air Sanitizers
DIS/TSS-11 / Sep. 3, 1980
EFFICACY DATA AND LABELING REQUIREMENTS:
Air Sanitizers
These requirements apply to products with label claims for the treatment
of air to reduce the numbers of airborne microorganisms.
(a) General. There is considerable evidence that glycol
vapors produce significant decreases i/n numbers of viable airborne bacteria
under relatively wide conditions of relative humidity and temperature
when properly and continuously dispensed by a vaporizing device so as
to maintain suitable concentrations in the air of enclosed spaces.
With dispensers for the intermittent treatment of air, such as pressurized
aerosols, several investigators have shown that glycols (triethylene,
dipropylene, or propylene glycol) at concentrations of 5% or more in such
formulations will temporarily reduce numbers of airborne bacteria when
adequate amounts are dispensed under relatively ideal conditions.
For other types of products intended for the treatment of air, claims
for reducing numbers of airborne microorganisms will be considered, providing
supporting experimental data are submitted to justify such claims.
(b) Test Standard. No standard method for evaluating air
sanitizers has been adopted. Refer to the attached references for information
on testing products intended for sanitizing the air of enclosed spaces.
Proposed testing protocols for studies of this kind may be submitted for
review and evaluation by the Agency prior to initiation of the tests.
(1) Glycol Products. For products containing at least 5% glycols
(triethylene, dipropylene, and/or propylene glycols), quantitative chemical
determinations must be performed, using an air sampling device, to show
the concentration of glycol vapor achieved with the product, used as
directed, in an enclosed experimental room or chamber. (Note: Until
the proposed Product Performance Guidelines are finalized, testing requirements
are being deferred for products of this type. Currently, efficacy requirements
are satisfied by the chemical formula statement showing appropriate
glycol content.) DIS/TSS-11 3 Sept. 80
(2) Other Products. For products other than those specified
in (b)(l), quantitative microbiological assays must be performed, using
an air sampling device, to show the level of reduction of viable microorganisms
achieved with the product, used as directed, in an enclosed experimental
room or chamber. The primary test bacteria are Staphylococcusaureus
ATCC 6538 and Klebsiellapneumoniae ATCC 4352. If the product
is intended for use in hospital or medical environments, tests with
Pseudomonasaeruginosa ATCC 15442 are also required.
(3) The methodology employed, such as spraying and sampling procedures,
and the environmental conditions in the room or chamber, such as temperature,
relative humidity, etc., must be reported. Raw data, as well as any
statistical or graphical interpretation of the results, must be included
in the reports.
(c) Performance Standard. For products containing at least
5% glycols, the results must show that adequate vapor concentrations (50%
saturation or more) are achieved in the air of the test enclosure. [Note:
See (b)(l) above for current policy in this regard.] For other products,
the results must show a viable count reduction of at least 99.9% over
the parallel untreated control, after correcting for settling rates, in
the air of the test enclosure with each of the required test bacteria.
(d) Claims. Adequate experimental data is available to
show that air sanitizers do not sterilize, disinfect, act as a germicide,
or protect experimental animals from infections by airborne bacteria or
viruses. Thus, claims of value in preventing or treating diseases, or
providing any other health protection, whether expressed or implied, are
not acceptable. Claims must clearly indicate the mitigating nature of
the activity, such as "Temporarily reduces the number of airborne
bacteria."
(e) Directions For Use. The label directions for use of
air sanitizers must state:
(1) That application be made in closed spaces ("Close all doors
and windows; close air vents or turn off air conditioners.");
(2) The duration and frequency of spraying;
(3) How the spraying should be conducted;
(4) The relative humidity necessary for maximum effectiveness.
With glycols and glycol mixtures intended for use in continuous vaporizing
devices, the vaporizers themselves do not require registration. However,
since their use is an integral part of the directions for use of the pesticide
product, the labeling used in connection with the sale of the vaporizer
is collateral to the labeling of the pesticide and must be submitted as
a part of the registration.
References
Bigg, E., B.H. Jennings, and F.C.W. Olsen. 1945. Epidemiological observations
on the use of glycol vapors for air sterilization. Am. J. Public Health
35:788-798.
Challinor, S.W. and J.P. Duguid. 1944. Propylene glycol as an air disinfectant.
I. Edinburgh Med. J. 51:280-289.
Dimmick, R.L. and A.B. Akers (Eds.). 1969. An Introduction to Experimental
Aerobiology. Wiley-Interscience, New York.
Greene, V.W., D. Vesley, R.G. Bond, and G.S. Michaelsen. 1962. Microbiological
contamination of hospital air. I. Quantitative studies. Appl. Microbiol.
10:561-566.
Gregory, P.H. and J.L. Monteith (Eds.). 1967. Airborne Microbes. Cambridge
Univ. Press, London.
Hall, L.B. 1962. Air sampling for hospitals. Hospital Topics 40:97-100.
Hamburger, M.J., O.H. Robertson, and T.T. Puck. 1945. The present status
of glycol vapors in air sterilization. Am. J. Med. Sci. 209:162-166.
Kerlan, I. 1950. Glycol vapors for air sanitation...the F.D.A. view.
Soap Sanitary Chem. 26(2):122-124.
Lester, W.,Jr., O.H. Robertson, T.T. Puck, and H. Wise. 1949. The rate
of bactericidal action of triethylene glycol vapor on microorganisms dispersed
into the air in small droplets. Am. J. Hyg. 50:175-188.
Lester, W.,Jr., S. Kaye, O.H. Robertson, and E.W. Dunklin. 1950. Factors
of importance in the use of triethylene glycol vapor for aerial disinfection.
Am. J. Public Health 40:813-820.
Lester, W.,Jr., E. Dunklin, and O.H. Robertson. 1952. Bactericidal effects
of propylene and triethylene glycol vapor on Escherichia coli. Science
115:379-382.
McConnell, W.J. 1949. An experiment with triethylene glycol vapor for
the control of colds among office workers. Ind. Med. 18:192-196.
McGray, R.J. 1970. A test method for the evaluation of air sanitization.
Proc. Chem. Specialties Manufact. Assoc., pp. 106-111.
Puck, T.T., O.H. Robertson, and H.M. Lemon. 1943. The bactericidal action
of propylene glycol vapor on microorganisms suspended in air. II. The
influence of various factors on the activity of the vapor. J. Exper. Med.
78:387-406.
Puck, T.T. 1947. The mechanism of aerial disinfection by glycols and
other chemical agents. II. An analysis of the factors governing the efficiency
of chemical disinfection of the air. J. Exper. Med. 85:729-757.
Robertson, O.H., E. Bigg, B.F. Miller, Z. Baker, and T.T. Puck. 1941.
Sterilization of air by certain glycols employed as aerosols and vapors.
Trans. Assoc. Am. Physicians 56:353-358; Science 93: 213-14.
Robertson, O.H. 1943. Sterilization of air with glycol vapors. Harvey
Lect. 38:227-254.
Robertson, O.H., B.F. Miller, and E. Bigg. 1943. Method of sterilizing
air. U. S. Patent No. 2,333,124.
Rosebury, T. 1947. Experimental Airborne Infection. Williams and Wilkens,
Baltimore.
Stuart, L.S. and J.L. Friedl. 1955. Testing aerosol products for germicidal
and sanitizing activity. Proc. Chem. Specialties Manufact. Assoc., pp.
93-97.
Wolf, H.W., et al. 1959. Sampling microbiological aerosols. Public Health
Service Publication No. 686, Washington.
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