The old fashioned treatment for urine contamination is to wash the rug in a vinegar bath and deodorize giving rug washers anywhere from limited to very good success. One refrain often heard on the discussion boards is who needs “expensive pretreatments” while vinegar is so cheap. That lead me to ask what does vinegar do and how good a treatment for urine contamination is it.
Common white vinegar is a great cheap and common source of Acetic acid. Vinegar is a 4 to 8% acetic acid solution with a pH of 2.4 to 3.5. It does have antimicrobial properties but in the concentrations common in rug washing it has very limited affect as a disinfectant. It also dissipates fairly rapidly in the wash bath which leads to problems but let us look at what vinegar does and doesn’t do.
The key is that the acid in vinegar increases substantivity in the wash bath for the wool fibers and their dyes. Substantivity is the attraction between the dye in the bath and the wool fibers. Dye has a negative charge and an acid increase the positive charge of the wool causing the dye to stay on the fiber. Remember playing with magnets as a child, the like ends; north to north repel each other but opposites north to south stick together. By making the wool a stronger positive it keeps the negatively charged dyes stuck to the wool. This is where the problem of vinegar comes in. Vinegar is referred to as a “soft acid” meaning that it is a plant acid and it dissipated in water. So while vinegar does a great job at the beginning of the wash bath it quickly releases and stops working. So at the end of the wash bath there is nothing to help holding the dye to the wool and this drastically increases the chance of dye instability. Maybe not in this wash cycle but perhaps in the next. So for that and a few other reasons chemists began to create the “expensive pretreatment” formulations.
So vinegar is acetic acid in primarily a water solution and water is less than an ideal solution to get the acid to the surface of the wool fiber. So most manufacturers use acetic acid primarily in alcohol which does a much better job of getting acid to fiber. They also increase the amount of acid in the solution. They cannot go too high since at about 25% the acid would destroy the cotton foundation. But if it were straight acetic acid in the solution we would still have the problem of the dissipation of the soft acid in the wash bath. So what they do is add a hard or mineral acid which does not dissipate. Then they add a surfactant to increase the effectiveness of the pretreatment. That is why you probably noticed that pretreatment is sudsy. This is the way that just about everyone makes their urine pretreatment. The exception is Chem Max which does all of this but adds a special deodorizer. Paul Lucas told me that for 22 years he made chemicals but never made urine pretreatment because he would just be copying everyone else. Then one day he came up with the idea of adding one more ingredient that has made a fantastic difference. The downside to Paul’s Urine Pretreatment is that his requires gloves, goggles, and vigorous flushing. The vigorous flushing is not a big deal since all the treatments involved a hard acid which has to be removed from the rug.
Keep in mind that vinegar has a limited antimicrobial capability the way we use it but the pretreatments have an effective antimicrobial affect because of the higher concentrations and the two acids. Urine is sanitary in a healthy animal when it is first sprayed and it is also acid. But it is rich in food for living organisms and can quickly foster a breeding ground for fungus, viruses, and other harmful microorganisms. It takes about 5 days for urine in a rug to shift from acid to alkaline and then over time the alkalinity can go as high as a pH of12.5. By that point the damage to the fibers and the health risk can be severe.
Today’s rug washer is faced with choices. They can continue to use vinegar which is not consistently substantive through the wash cycle, has limited penetration, and is not an effective antimicrobial agent. Or they can switch to urine pretreatment with consistent substantivity, better penetration to get the acid where it is needed and a safe sanitizing treatment of a rug. Today’s rug washer has to decide whether to save a few cents and take the risk of long term damage to the clients rug as well as long term risk to the health and well being of the client. For the sake of a dollar or two. Effective modern urine pretreatment can
Then there is the question of speed and effectiveness, on a badly urine contaminated rug it is not unusual to see Rug Washers I know wash a rug more than once to deal with urine odor. Does it make sense to wash a rug once and spend an extra $25 in chemicals or wash it two or 3 times for the same money and save $25. It really comes down to how busy you are, how much your time is worth and how important the end result is to you. What does it say about your reputation if the urine odor returns on humid days? Personally I would rather decrease total man hours and turn out a better profit. If you are at $3 per square foot and you have to wash it twice you are at $1.50 a square and at three times. Additionally many Rug Wasters are charging an additional dollar a square foot for urine treatment. At that point instead of a decrease to the profit margin it becomes a profit center.
There are many great prod ducts on the market today. Personally I would choose ChemMax Urine Pretreatment if I don’t mind the goggles and gloves otherwise I would use Bridgepoint’s TCU Neutralizer. For faster more effective cleaning with greater profit I think it is time to send vinegar back to the kitchen.
A major point that I forgot to mention about Bridgepoint’s TCU Neutralizer. I chose it because it includes solvents that can break down the Lipids in urine. Fats, Oils, Waxes, and even excess Vitamins can be a major problem in sever urine contamination. TCU has the power to break them up and make the job much easier. No matter how well TCU works I don’t expect to use it again. Watch for a special wool balanced replacement very soon.