Many homemakers often turn to commercial oven cleaners to clean out their ovens in order to save time in cleaning. Oven cleaners are made with strong chemicals, the major one being sodium hydroxide, or lye. It's a strong alkaline, or base, with a pH of nearly 14. Fortunately, vinegar offers an easy way to neutralize sodium hydroxide. Vinegar's acidic nature is a perfect counterbalance to lye's alkalinity.
Almost all commercial over-the-counter oven cleaners make use of either sodium hydroxide or potassium hydroxide. These substances are both extremely alkaline, and their odors can irritate eyes and nasal passages. They do their work well because of their alkaline nature, and oven stains are often no match for them. However, if too much is used or the cleaner's chemicals permeate an oven, lingering fumes can result and require a neutralizing agent.
Common vinegar is very weak chemical acetic acid, and it's used in a variety of food preparation processes. In chemistry, the best way to counteract the effect of an alkaline solution is to apply an acid solution to it until the pH is is brought down to manageable levels. Vinegar itself has a pH range of 2.4 to 3.4, meaning it is sufficiently acidic to serve as a useful neutralizing agent against most alkaline agents.
pH is the secret behind how vinegar can neutralize lye-based oven cleaners. Because it's an acid and low in pH, it can, in effect, "pull" the highly alkaline pH level of an oven cleaner back down to tolerable levels. That can make it helpful in dealing with strong odors from oven cleaners. It can also be used to neutralize oven cleaner on skin, too.
Perfectly neutral pH is 7.0. However, it's not necessary for vinegar to pull oven cleaner all the way down to that level to be effective. Reducing it to 9.0 or so often is more than sufficient to reduce odor. In most cases, you should apply 100 percent vinegar. However, oven cleaner odors on many sprayed surfaces can often be handled with a 50/50 water-to-vinegar solution. You may still adjust strength upward based on need, though.