Dilution Ratios and Conversions

What it is

Concentrated cleaners and disinfectants are sold to be mixed with water. The label states the dilution as a ratio (1:64), as ounces per gallon (2 oz/gal), or as a range for light, medium and heavy soil. For EPA-registered sanitizers and disinfectants the label directions are legally binding: using a registered pesticide in a manner inconsistent with its labeling is unlawful under FIFRA, and an under-diluted product may not deliver the claimed kill. Over-concentration wastes product, leaves residue and can raise exposure.

How to identify the ratio form

• "1:64" or "1 to 64" usually means 1 part concentrate to 64 parts water. Some labels mean 1 part in 64 total. Read the label's own wording.
• "oz per gallon" is the most direct form; use it when present.
• "ppm" (parts per million) is used for sanitizers and chlorine. 1% = 10,000 ppm.

Conversion table (1 part concentrate to X parts water)

US gallon = 128 fl oz; quart = 32 fl oz. Ounces of concentrate = water volume in ounces ÷ X.

Key points

• Always add concentrate to water, not water to concentrate, unless the label says otherwise; it limits splashing and heat.
• Use a dispensing system, measuring cup or portion pack. "Glug" dosing is the main cause of wrong dilutions.
• Cold vs warm water, and hard water, can affect some products; follow the label.
• Some disinfectants list a different dilution for each claim (e.g. a higher strength for certain organisms). Use the strength for the organism you need.
• Label every secondary container with the product name and hazards (29 CFR 1910.1200(f)(6)). Diluted product may have a shorter useful life; follow the label on discard intervals.
• Verify sanitizer strength with the test strip the label or Food Code calls for.

Common mistakes

• Assuming "more is stronger and better".
• Reusing a spray bottle labeled for a different product.
• Applying a cleaning ratio to the disinfecting claim.
• Mixing two concentrates in one bottle.

Governing standards: 40 CFR Part 156 (labeling); FIFRA, 7 U.S.C. 136j(a)(2)(G); 29 CFR 1910.1200(f)(6); FDA Food Code 4-501.114 for food-contact sanitizers.

Reference only. Verify against the current governing code or standard, the manufacturer's data and the project documents before use. Apps for Distributors disclaims liability arising from reliance on this reference.