Disinfectants
Common Disinfectants
| Chemical Compound | Gram + Bacteria | Gram - Bacteria | TB-like Bacteria | Fungi | Virus | Best pH range for activity | Activity when organic matter present | Common uses ** |
|---|---|---|---|---|---|---|---|---|
| Chlorhexidine | SA* | SA | SA | SA | Most | Wide range | Good | E/P/F |
| Formaldehyde and aldehydes | ++ | ++ | ++ | ++ | ++ | Wide range | Good | E/P/F |
| Chlorine Chloramines | ++ | ++ | SA | ++ | SA | Acid | Very poor | CS/E |
| Iodophors | ++ | ++ | SA | ++ | SA | Acid | Fair to poor | CS/E |
|
Sodium hydroxide (Lye) |
++ | ++ | SA | ++ | ++ | Alkaline | Good | P |
| Quaternary ammoniums | ++ | + | No | SA | SA | Alkaline | Fair | CS/E |
| Phenols | ++ | ++ | + | SA | SA | Acid | +Good | E/P/F |
* SA-some activity
**E-equipment; P-premises; F-footbaths; CS-clean surfaces
(Adapted from Purdue University Extension Bulletin PIH80)
Bleach Dilutions
- Commercial chlorine bleach contains 5.25% sodium hypochlorite in aqueous solution and 50,000 ppm available chlorine.
- Bleach has no detergent activity, always requires extensive cleaning beforehand.
- Stability when diluted is 24 hours.
- Recommended contact time is 10 minutes. Rinse is required.
| Sodium hypochlorite % | Bleach Solution Ratio | Bleach Dilution | ppm (available chlorine) |
Comments **Always use on cleaned surfaces. |
|---|---|---|---|---|
| 0.025% | 1:200 |
1.5 Tbsp (0.6 oz) bleach to 1 gallon water |
250 ppm | Common household use |
| 0.1% | 1:50 | 1/8 C (1 oz.) bleach to 1 gallon water | 1000 ppm | Commonly used |
| 0.16% | 1:32 |
1/2 cup (4 oz.) bleach to 1 gallon water |
1562.5 ppm | Commonly used |
| 0.5% | 1:10 | 1.5 cups (12 oz.) bleach to 1 gallon water | 5000 ppm | This is a very strong solution and should be used on a limited basis. |