A chlorine solution is a common and effective disinfectant used across various settings, from homes to commercial kitchens. The goal of making a 200 parts per million (PPM) chlorine solution is to create a sanitizing agent strong enough to kill microorganisms without being overly corrosive or hazardous. This specific concentration is the standard for sanitizing non-porous surfaces that come into contact with food, as well as high-touch areas like doorknobs and counters. Preparing this solution requires careful attention to the initial concentration of the household bleach and precise mixing techniques.
Understanding the Variables: Bleach Concentration and PPM
Understanding the term PPM is the first step in correctly preparing a sanitizing solution. PPM, or parts per million, is a measurement of concentration, aiming for 200 milligrams of available chlorine per liter of water for general sanitizing purposes.
The concentration of the liquid chlorine bleach used as the starting material is the primary variable. Household bleach is an aqueous solution of sodium hypochlorite, typically ranging from 5.25% to 8.25% sodium hypochlorite by weight. Using an outdated ratio intended for a 5.25% product with a more concentrated bleach will result in a solution significantly stronger than the 200 PPM target. Therefore, checking the label for the exact percentage of sodium hypochlorite is necessary before measuring and mixing.
Calculating and Mixing the 200 PPM Solution
The calculation for a 200 PPM solution is a simple dilution ratio based on the bleach’s starting concentration. Since the goal is 200 PPM, the necessary volume of bleach decreases as its starting percentage of sodium hypochlorite increases. It is always recommended to use measuring spoons and cups for accuracy, avoiding estimation for sanitizing applications.
Mixing Ratios Per Gallon of Water
For a gallon of water, the required amount of household bleach varies depending on the product’s label strength.
If the product is the older standard strength of 5.25% sodium hypochlorite, mixing three level teaspoons (one tablespoon) into one gallon of water will yield the target 200 PPM concentration.
A slightly more concentrated bleach, such as the 6.0% formula now common in many stores, requires approximately two and a half teaspoons mixed into one gallon of water.
Highly concentrated bleach products, often labeled as 8.25% sodium hypochlorite, require only two level teaspoons per gallon of water to achieve the desired strength.
When mixing, begin with the water in the container first, and then slowly add the measured amount of bleach, rather than the reverse. Always use cool or room-temperature water for dilution, since hot water can accelerate the chemical breakdown of the active chlorine compound.
Essential Safety and Handling Procedures
Working with chlorine solutions requires specific safety measures to prevent chemical exposure and ensure efficacy. Always wear protective equipment, such as impermeable gloves and eye protection, when handling the concentrated bleach or the mixed solution. Proper ventilation is also important to avoid inhaling the chlorine vapor released during the mixing process.
A fundamental rule is the prohibition against mixing the bleach solution with other cleaning chemicals. Combining bleach with any product containing ammonia creates highly toxic chloramine gas, and mixing it with acids, like vinegar, generates poisonous chlorine gas.
The prepared 200 PPM solution must be made fresh daily because the active sodium hypochlorite degrades rapidly once diluted. Any leftover solution must be discarded after 24 hours to ensure the required sanitizing strength is maintained.
The mixed solution should be stored in an opaque, labeled container to protect it from light and heat and to clearly identify the contents. Exposure to light and heat accelerates the breakdown of the sodium hypochlorite, reducing its effectiveness over time. Keeping the container tightly sealed and in a cool, dark location helps to slow this degradation.