ABSTRACT
Introduction: Chemical germicides are important in infection control. However, there are mounting concerns on the human and environmental safety of many germicidal products in use today. Whereas it may be difficult to find formulations that are effective while being totally safe, this paper describes the broad-spectrum germicidal activity of Virox, a product based on accelerated and stabilized hydrogen peroxide; it contains ingredients that are considered safe for humans and benign to the environment.
Objective: The objective was to test the sporicidal, mycobactericidal fungicidal, bactericidal and virucidal activities of Virox to determine its potential as a broad-spectrum germicide.
Materials & Methods: Three separate lots of the product were tested. The quantitative carrier test used met the requirements of the Canadian General Standards Board to assess germicides for use on environmental surfaces and medical devices. Standard strains of Bacillus subtilis, Clostridium sporogenes, Mycobacterium terrae, Trichophyton mentagrophytes, Poliovirus type 1(Sabin), Staphylococcus aureus, Salmonella choleraesuis and Pseudomonas aeruginosa were used. The soil load was 5% bovine serum and standard hard water (200 ppm calcium carbonate) was the product diluent. Depending on type of activity assessed and the temperature, the contact time ranged from one minute to six hours.
Results: At 20C, the undiluted product was sporicidal in six hours, mycobactericidal in 20 minutes and fungicidal in five minutes. When diluted 1:16 in hard water, it proved to be bactericidal in one, three and 10 min at 45, 20 and 4C, respectively; it was virucidal in five minutes at 20C.
Conclusions: All three lots of the product proved to be sporicidal, mycobactericidal and fungicidal at full strength, and virucidal and bactericidal at a 1:16 dilution. The product is therefore suitable for use as a high level disinfectant and is safer than many other broad-spectrum germicides.
Key Words: Accelerated and stabilized hydrogen peroxide, infection control, virucide, bactericide, sporicide, fungicide, mycobactericide.
EDITORIAL COMMENT
In a journal that attempts to separate commercialism from science, it is sometimes expedient to publish meaningful information from a source that has a connection with the dental industry. This article presents an effective product with a safe environmental report.
R.A. Clappison, DDS, FRCD(C), Infection Control and Health Issues Consultant, Oral Health
Table 1: The sporicidal activity of full-strength Virox at 201C in a contact time of six hours.
| Product Lot Number | CFU/Control carrier | CFU/test carrier | Log10 Reduction |
| 007 | 1.96 x 108 | 0 | >8 |
| 008 | 1.96 x 108 | 0 | >8 |
| 009 | 1.56 x 108 | 0 | >8 |
| 007 | 3.12 x 107 | 0 | >7 |
| 008 | 3.12 x 107 | 0 | >7 |
| 009 | 1.36 x 107 | 0 | >7 |
Table 2: The activity of full-strength Virox against Mycobacterium terrae at 201C in a contact time of 20 minutes.
| Product Lot | CFU/Control | CFU/test | Log10 | Number | carrier | carrier | Reduction |
| 007 | 2.53 x 106 | 0 | >6 | ||||
| 008 | 1.78 x 106 | 0 | >6 | ||||
| 009 | 1.86 x 106 | 0 | >6 |
Table 3: The activity of full-strength Virox against the conidia of Trichophyton mentagrophytes at 201C in a contact time of 5 minutes.
| Product Lot | CFU/Control | CFU/test | Log10 | Number | carrier | carrier | Reduction |
| 007 | 5.40 x 105 | 0 | >5 | ||||
| 008 | 4.00 x 105 | 0 | >5 | ||||
| 009 | 4.00 x 105 | 0 | >5 |
Table 4: The activity of a 1:16 dilution of Virox against Pseudomonas aeruginosa.
| Product Lot | Contact | Contact | CFU/Control | CFU/test | Log10 | Number | Temperature | time | carrier | carrier | Reduction |
| 007 | 20C | 3 min | 1.96 x 106 | 0 | >6 | ||||||
| 008 | 1.96 x 106 | 0 | >6 | ||||||||
| 009 | 1.25 x 106 | 0 | >6 | ||||||||
| 007 | 4C | 10 min | 1.79 x 106 | 0 | >6 | ||||||
| 008 | 1.79 x 106 | 0 | >6 | ||||||||
| 009 | 1.25 x 106 | 0 | >6 | ||||||||
| 007 | 45C | 1 min | 1.45 x 106 | 0 | >6 | ||||||
| 008 | 1.45 x 106 | 0 | >6 | ||||||||
| 009 | 2.27 x 106 | 0 | >6 |
Table 5: The activity of a 1:16 dilution of Virox against Staphylococcus aureus.
| Product Lot | Contact | Contact | CFU/Control | CFU/test | Log10 | Number | Temperature | time | carrier | carrier | Reduction |
| 007 | 20C | 3 min | 1.66 x 106 | 0 | >6 | ||||||
| 008 | 1.77 x 106 | 0 | >6 | ||||||||
| 009 | 1.77 x 106 | 0 | >6 | ||||||||
| 007 | 4C | 10 min | 1.68 x 106 | 0 | >6 | ||||||
| 008 | 1.68 x 106 | 0 | >6 | ||||||||
| 009 | 1.68 x 106 | 0 | >6 | ||||||||
| 007 | 45C | 1 min | 1.79 x 106 | 0 | >6 | ||||||
| 008 | 1.79 x 106 | 0 | >6 | ||||||||
| 009 | 2.40 x 106 | 0 | >6 |
Table 6: The activity of a 1:16 dilution of Virox against Salmonella cholerasius.
| Product Lot | Contact | Contact | CFU/Control | CFU/test | Log10 | Number | Temperature | time | carrier | carrier | Reduction |
| 007 | 20C | 3 min | 3.86 x 106 | 0 | >6 | ||||||
| 008 | 3.86 x 106 | 0 | >6 | ||||||||
| 009 | 2.38 x 106 | 0 | >6 | ||||||||
| 007 | 4C | 10 min | 1.65 x 106 | 0 | >6 | ||||||
| 008 | 1.65 x 106 | 0 | >6 | ||||||||
| 009 | 2.38 x 106 | 0 | >6 | ||||||||
| 007 | 45C | 1 min | 1.16 x 106 | 0 | >6 | ||||||
| 008 | 1.16 x 106 | 0 | >6 | ||||||||
| 009 | 1.11 x 106 | 0 | >6 |
Table 7: The activity of a 1:16 dilution of VIrox with an anti-foam against three types of vegetative bacteria after a contact time of one minute at 45C*.
| Test organism | CFU/Control carrier | CFU/test carrier | Log10 Reduction | |
| Pseudomonas aeruginosa | 2.27 x 106 | 0 | >6 | |
| Staphylococcus aureus | 1.40 x 106 | 0 | >6 | |
| Salmonella choleraesuis | 1.11 x 106 | 0 | >6 | |
* Lot#009 was tested in these experiments
Table 8: The activity of a 1:16 dilution of Virox against Poliovirus type 1 (Sabin) at 20C with a contact time of five minutes.
| Product Lot Number | Input control | PFU/Control carrier | PFU/test carrier | Log10 Reduction |
| 007 | 8.3 x 106 | 8.7 x 104 | 1.34 | 4.8 |
| 008 | 8.3 x 106 | 8.7 x 104 | 1 | 4.9 |
| 009 | 8.3 x 106 | 8.7 x 104 | 10 | 3.94 |
Table 9: The effect of diluted Virox on the plaque-forming ability of the poliovirus.
| Plaques on cell | Plaques on cell monolayers pre-exposed | Plaques on cell monolayers | monolayer controls | 1/100 dilution of the test product | pre-exposed to EBSS |
| 0 | 7 | 5 | |||
| 0 | 5 | 7 | |||
| 0 | 6 | 5 | |||
| – | 7 | – | |||
| – | 5 | – | |||
| – | 4 | – | |||
| MeanSD | 5.671.1 | 5.831.24 | |||
Cell monolayers were first exposed to either a 1:100 dilution of the test product or EBSS and incubated for 30 minutes at 37C. They were then washed with EBSS and inoculated with the virus for plaque assay. Cell control monolayers were treated in the same way but did not receive any virus. (- = not done)
Table 10: The effectiveness of dilution/neutralization as a means of arresting the virucidal activity of Virox.
| Plaques on cell monolayers exposed | Plaques on cell monolayers | Plaques on cell | to one part virus mixed with nine parts | exposed to one part virus mixed | monolayer control | of a 1/100 dilution of the test product | with nine parts EBSS | |
| 0 | 5 | 5 | ||||||
| 0 | 3 | 3 | ||||||
| 0 | 4 | 4 | ||||||
| – | 3 | – | ||||||
| – | 5 | – | ||||||
| – | 9 | – | ||||||
| MeanSD | 4.832.03 | 4.00.82 | ||||||
One part of the virus was mixed with either the diluted test product or EBSS and held at room temperature for five minutes. Plaque assays were then carried out. Cell monolayer controls received EBSS only. (- = not done)
References are available from the Managing Editor of Oral Health.
The product mentioned as Virox is marketed as Optim and is available in Canada through SciCan, a division of Lux and Zwingenberger Ltd.
R.A. Clappison, DDS, FRCD(C), Infection Control and Health Issues Consultant, Oral Health
