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.