GB2211414A - Method and composition for disinfecting poultry houses and other premises - Google Patents

Abstract

Poultry houses and other premises are disinfected or fumigated by the introduction into them, by pressure spraying or fogging, a dilute aqueous glutaraldehyde solution additionally containing 1,2-propylene glycol at a glycol:glutaraldehyde weight ratio in the range 1:1 to 4:1, the solution being introduced into the premises at a pH of at least 7 when diluted with town mains water. A cationic germicide is preferably also included, e.g. benzalkonium chloride.

Description

METHOD AND COMPOSITION FOR DISINFECTING POULTRY HOUSES AND OTHER PREMISES This invention relates primarily to a method and composition for disinfecting poultry houses and incubators, although the method and composition may be used for disinfecting any livestock premises or in other situations exposed to the hazards of infection.

Poultry houses and equipment are subject to infection with a wide variety of disease-producing agents, the most serious of which are viruses, which cause heavy economic losses, both due to mortality and the limitation of normal production performance. Among these is Newcastle Disease, which is caused by the Fowl Pest Virus, a Paramyoxvirus, and which is a Notifiable disease under the UK Diseases of Animals Act.

For many years the most widely used chemical for disinfection, applied both as a surface disinfectant and as a fumigant by various techniques, has been formaldehyde, which has been applied in its basic form as a gas, in solution, or combined with other germicidal chemicals.

The principles upon which the widespread adoption of formaldehyde was based were discussed extensively by E G Harry in a paper presented to the 10th World Poultry Congress. Harry showed that the vapour pressure of formaldehyde was the major characteristic affecting its performance and value as a germicide by influencing its distribution and deposition on surfaces and the rate of loss from surfaces into the atmosphere.

In recent time the use of formaldehyde has been questioned, since the high atmospheric levels that persist following its application as a surface disinfectant have been alleged to be not only irritant but also potentially carcinogenic. As a result there is a need for an alternative disinfectant composition that can be applied both as a surface disinfectant and by fumigation.

The disinfectant activity of the higher aldehydes, particularly dialdehydes, is well known. There are many examples of the performance of these materials used alone or in admixture with one another or with formaldehyde.

U.S. Patent No. 3,106,328 discloses sporicidal compositions comprising an aqueous or alcoholic solution of C2-C6 saturated dialdehyde such as glutaraldehyde, at a pH of above 7.4.

U.S. Patent No. 3,282,775 discloses sporicidal compositions comprising a C2-C6 saturated dialdehyde such as glutaraldehyde and a cationic surfactant.

U.S. Patent No. 3,697,222 discloses sterilization processes utilizing aqueous acidic glutaraldehyde and ultrasound.

U.S. Patent No. 3,708,263 discloses low-temperature sterilization using aqueous glutaraldehyde (pH 2 to 7.4) and dimethylsulphoxide.

U.S. Patent No. 3,983,252 discloses disinfectant compositions containing a dialdehyde, e.g. glutaraldehyde, and an alkali metal salt, e.g.

sodium citrate, as stabilized disinfectant compositions for disinfecting medical and surgical supplies, and as a household disinfectant. According to that disclosure the stabilizing effect of the alkali metal salt, e.g. sodium citrate, on neutral or alkaline glutaraldehyde solutions is further improved by the addition of inter alia a diol, e.g. propylene glycol, in amounts ranging from 0.25 to 50% by weight of the composition, i.e. diol:glutaraldehyde ratios of 500:1 to 1:12, preferably from 5:1 to 1:2, the diol operating synergistically with the alkali metal salt. On the other hand, it is disclosed that solutions of glutaraldehyde and diol alone, i.e. without the alkali metal salt, are of good stability but inferior as a disinfectant.

U.K. Patent No. 1,499,448 discloses disinfecting medical and surgical instruments using an aqueous oxydiacetaldehyde, in place of glutaraldehyde.

U.K. Patent No. 1,602,653 reports that glutaraldehyde solutions are not ordinarily sporicidal at room temperature at acid pH, but can be made so by addition of alkali, although such alkaline solutions are unstable.

Finally European Patent Specification EP-A-0 046 375 reports that improved disinfecting and sterilizing compositions with low odour and irritation potential are provided by aqueous solutions containing a C2-C6 dialdehyde and a diol or monosubstituted diol of the formula RO(CH2CH2O)nCH2CH2OH, where R is H or CH3 and n has a value of from 1 to 22. Such compositions are useful at pHs in the range 2 to 9, and it is claimed that they have excellent sporicidal activity. This is in particular in comparison with similar compositions comprising monomeric, rather than polymeric, diols and triols as the polyol component, that is to say monomeric diols and triols such as ethylene glycol, propylene glycol, butylene glycol and glycerol.Comparative data are presented to show that, in 2.5% aqueous glutaraldehyde solutions, the addition of 20% monomeric diol (i.e. a diol:glutaraldehyde ratio of 8:1), such as ethylene glycol or propylene glycol, the sporicidal activity of the glutaraldehyde is substantially reduced. In particular instances, the sporicidal activity against B.subtilis spores at a pH of 7.5 is reduced by the following values:: Diol Failure Rate None (i.e. 2.5% aqueous glutaraldehyde) 0/30 20% ethylene glycol 16/30 20% 1,2-propylene glycol 11/30 20% 1,3-propylene glycol 30/30 20% 1,2-butane diol 30/30 20% 1,3-butane diol 30/30 20% 1,4-butane diol 30/30 It is speculated that such reduction in sporicidal activity is the result of stable cyclic acetal formation betwen the glutaraldehyde and the monomeric diol, which does not occur when polymeric diols are used, i.e. diol condensates and ethers of the formula R(CH2CH2O)nCH2CH2OH.

It has now been unexpectedly discovered that the use of dilute aqueous glutaraldehyde solutions containing 1,2-propylene glycol and also preferably a cationic germicide in certain well defined proportions results in substantially less vapour emission than pure glutaraldehyde solutions of comparable level of active content. Thus, the application of such solutions to disinfecting and fumigating premises such as poultry houses is less hazardous. Moreover, and more significantly from the economic point of view, the premises can be safely entered and restocked after disinfection or fumigation, thus reducing the time that the house is out of commission between the marketing of the poultry and restocking.

The present invention, in accordance with a first aspect, provides a method of disinfecting or fumigating poultry houses and other premises, which comprises introducing therein by pressure spraying or fogging an aqueous disinfectant solution, in which the disinfectant solution is a dilute aqueous glutaraldehyde solution additionally containing 1,2-propylene glycol at a glycol:glutaraldehyde weight ratio in the range 1:1 to 4:1, and in which the solution is introduced into the premises at a pH of at least 7 when diluted with town mains water.

The present invention, in accordance with a second aspect, also provides an aqueous disinfectant composition comprising an aqueous solution of 1,2-propylene glycol and glutaraldehyde at a weight ratio in the range 1:1 to 4:1.

The glycol:glutaraldehyde weight ratio is preferably 1.5:1 to 2.0:1 and the pH from 7 to 8. The solution conveniently contains 2 to 22, preferably 3 to 12, weight per cent of glutaraldehyde.

It is especially preferred that the solution of the present invention and the solution used in accordance with the present invention should also contain a cationic germicide such as benzalkonium chloride. In this case, preferably the weight ratio of glutaraldehyde to cationic germicide is in the range 3:1 to 1.5:1 and the weight ratio of monopropylene glycol to cationic germicide is in the range 6:1 to 3:1.

Whereas the teaching of US Patent 3,282,775 discloses a composition based upon a dialdehyde and a cationic surfactant, this invention yields a disinfectant with enhanced, synergistic viricidal properties by combining glutaraldehyde, a cationic germicide and monorpopylene glycol, in specific ratios and concentrations.

The prior art teaches that by the use of various alkalinating agents, surfactants, etc., stable glutaraldehyde formulations are produced with sporicidal properties of value in medical and surgical procedures.

These properties are demonstrated with formulations using glutaraldehyde alone, or admixture with other aldehydes, including formaldehyde.

TEST PROCEDURES Muelman and Halen (Veterinary Record (1982) 111,412-413), demonstrated that glutaraldehyde alone was inferior to a mixture of glutaraldehydelformaldehydelcationic germicide against viruses responsible for diseases of economical significance to poultry production. This work also demonstrated that the ratio of the chemicals in the mixture was critical.

Test Product Concentration In Test ppm At Test Dilution Performance Formaldehyde 37,000 + Glutaraldehyde 1,000 +++ + Cationic Germicide 2,000 Chlorine 2,500 +++ +++ Mixture A: Glutaraldehyde 1,000 ) Formaldehyde 1,000 ) ++ ++ Cationic Germicide 1,000 ) Mixture B: Glutaraldehyde 500 ) Formaldehyde 750 ) +++ +++ Cationic Germicide 600 ) Note: +++ indicates totally effective - indicates ineffective In the United Kingdom the approval and endorsement of disinfectants used in Animal Health situations is controlled by the Diseases of Animals Act and its various Regulations. Evaluations can only be carried out by Government Agencies using Statutory Test procedures. For poultry this involves the testing of disinfectants against the Fowl Pest or Newcastle Disease virus, which is a Paramyxovirus.Tests commissioned with a Government approved Agency on disinfectants based upon Mixture B, which had previously been shown by Muelman and Halen to be an effective viricide, confirmed this performance against the Fowl Pest Virus. The findings indicated some slight fall-off in performance in that 17-20% more active material was required to achieve the effective performance criteria, using the Statutory test procedures.

The incorporation of a Polyglycol was shown to inhibit performance to the extent that 14-15% more active material was required to achieve the same level of performance, as mixtures not incorporating this material. The ratio of glycol to glutaraldehyde was 2.5:1 and the ratio to total aldehyde 1:1.

Test Product Concentration In ppm At Effective Test Dilution Mixture B Glutaraldehyde 558 Formaldehyde 895 Cationic Germicide 706 Mixture C Glutaraldehyde 576 Formaldehyde 877 Cationic Germicide 692 Mixture D Glutaraldehyde 666 Formaldehyde 1066 Cationic Germicide 800 Polyethylene Glycol 1600 Further evaluations were carried out by the Statutory Testing Agency on mixtures that omitted the formaldehyde and incorporated propylene glycol in addition to a cationic germicide.

The ratios of these materials were varied so as to identify any inhibitory or synergistic influences on the viricidal performance of the glutaraldehyde.

The results obtained indicate that the preferred ratio of propylene glycol to glutaraldehyde is from 1.5:1 to 2.0:1 and that of glutaraldehyde to cationic germicide from 2.8:1 to 1.6:1.

Using Statutory Test procedures against a virus of economic significance to the poultry industry, this invention demonstrates a disinfectant formula that: (i) excludes formaldehyde, now known to be a serious health hazard; (ii) potentiates the viricidal properties of glutaraldehyde in a synergisitic complex incorporating a cationic germicide and propylene glycol; (iii) is stable in concentrated form with a normal pH of 6.2-6.5; which upon dilution with town mains tap water, will achieve a pH in excess of 7 and preferably in excess of 7.5 without the benefit of any inorganic alkaline adjuvant; and (iv) has low vapour release characteristics, which results in limited gaseous contamination of the working environment and so contains the active viricidal complex on the surfaces to which it is applied.

The surgical and medical applications for which the sporicides of the quoted prior art were designed involve the immersion of objects in solutions, or the circulation of solutions through complex equipment (e.g. respirators), or the swabbing down of contaminated surfaces.

In the livestock industry animals are housed in large buildings with floor areas of 1000 square metres and 2500 square metres of total surface area to be disinfected contained within a space of 2500 cubic metres.

In this physical environment disinfection is normally carried out by broadcast application of prepared solutions by pressure spraying or aerosol fumigation methods. These procedures would result in rapid depletion of any volatile vapour producing chemical, from the treated surfaces, into the atmosphere and a resultant failure of disinfection performance.

The use of a surfactant aids in penetration of contaminated soil and surfaces. Non-ionic surfactants tend to interfere with the germicidal action: cationic surfactants are the most effective germicides, e.g. quaternary ammonium compounds such as benzalkonium chloride. The present invention aims to use the glutaraldehyde, which is the most expensive ingredient, economically. Monopropylene glycol serves as a humectant and retains the residue on the surface in an active phase.

As indicated, the disinfectant solutions used in accordance with this invention are characterised by reduced irritancy, enabling the fumigated premises to be entered after a relatively short space-of time. It has also been observed that the presence of the glycol helps to make the droplet size in the spray or fog more uniform, thus leading to more uniform treatment of surfaces, and helps to delay drying out on the surfaces (owing to its humectant properties) and thus to prolong the germicidal activity.

The invention is illustrated by the following Examples.

EXAMPLE I A disinfectant composition for application by pressure spraying in high volume to surfaces of buildings and equipment, e.g. 25 litres solution per 100 m2, was prepared by mixing the following ingredients: 50% aqueous solution of glutaraldehyde 24% 1,2-propylene glycol 24% cationic germicide (benzalkonium chloride) 6% water (additional) 4696 The mixture was diluted 1/200, i.e. 1 litre of mixture to 200 litres of water, in a drum.The diluted mixture was applied by a high pressure pump, at a rate of 9 to 14 litres (2 to 3 gallons) per minute at 7 to 8 MPa using a wide-angled jet (90-125 ) so as to thoroughly drench the structural surfaces (walls, floors, roof lining) of a livestock house. 500 litres of solution was found to effectively treat/disinfect 2000 m2 of surface (a typical broiler house) and workers could enter the house without special protection against harmful vapours after 3 or 4 hours.

EXAMPLE II A disinfectant composition for application by aerosol/fogging using a conventional thermal fog generator, e.g. 25 litres of solution per 1000 m2/2500 m2 broiler product house, was prepared by mixing the following ingredients: 50% aqueous solution of glutaraldehyde 20% 1,2-propylene glycol 20% cationic germicide (benzalkonium chloride) 5% water (additional) 55% The mixture was diluted 1/5 with water, i.e. 5 litres of mixture to 20 litres of water, and the diluted mixture was applied by a thermal generator at a rate of 1 litre per minute to produce 2500 m3 of gas/aerosol mixture to 2 3 fill the available airspace in a 1000 m2/2500 m3 broiler house. This treatment effectively fumigates/disinfects the house surfaces, and workers could enter the house without special protection against harmful vapours after 3 or 4 hours.

EXAMPLE III A disinfectant composition was made up as follows: 50% aqueous solution of glutaraldehyde 4% 1,2-propylene glycol 4% cationic germicide (benzalkonium chloride) 1% water 91% which is a ready for use aerosol/fogging solution.

The pH of these compositions will be found to be within the range 6.0-6.7, ideally pH 6.3-6.5.

Solutions prepared prior to use by dilution in town mains tap water will demonstrate an alkaline pH - as follows: Diluted 1/5 pH 7.1-7.2 Diluted 1/100 pH 7.5-7.8 Diluted 1/200 pH 7.8-8.0

Claims (16)

1. CLAIMS 1. A method of disinfecting or fumigating poultry houses and other premises, which comprises introducing therein by pressure spraying or fogging an aqueous disinfectant solution, in which the disinfectant solution is a dilute aqueous glutaraldehyde solution additionally containing 1,2propylene glycol at a glycol:glutaraldehyde weight ratio in the range 1:1 to 4:1, and in which the solution is introduced into the premises at a pH of at least 7 when diluted with town mains water.
2. 2. A method according to Claim 1, in which there is used a dilute aqueous glutaraldehyde solution containing 1,2-propylene glycol at a glycol: glutaraldehyde weight ratio in the range 1:1 to 2:1.
3. 3. A method according to Claim 2, in which the said ratio is in the range 1.5:1 to 2.0:1.
4. 4. A method according to any one of Claims 1 to 3, in which the said solution has a pH in the range 7 to 8.
5. 5. A method according to any one of Claims 1 to 4, in which the disinfectant solution additionally contains a cationic germicide.
6. 6. A method according to Claim 5, in which the germicide is benzalkonium chloride.
7. 7. A method according to any one of Claims 1 to 6, in which the disinfectant solution contains from 2 to 22 wt.% glutaraldehyde.
8. 8. A method according to Claim 7, in which the solution contains 2 to 12% glutaraldehyde.
9. 9. An aqueous disinfectant composition comprising an aqueous solution of 1,2-propylene glycol and glutaraldehyde at a weight ratio in the range 1:1 to 4:1.
10. 10. A composition according to Claim 9, in which the ratio is in the range 1:1 to 2:1.
11. 11. A composition according to Claim 10, in which the ratio is in the range 1.5:1 to 2.0:1.
12. 12. A composition according to Claim 9, 10 or 11, that additionally contains a germicide.
13. 13. A composition according to Claim 12, in which the germicide is cationic.
14. 14. A composition according to Claim 13, in which the weight ratio of glutaraldehyde to cationic germicide is in the range 3:1 to 1.5:1 and the weight ratio of monopropylene glycol to cationic germicide is in the range 6:1 to 3:1.
15. 15. A method according to Claim 1, substantially as hereinbefore described with reference to Example I, II or III.
16. 16. A composition according to Claim 9, substantially as hereinbefore described with reference to Example I, II or III.