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Ask Dr. Laundry

Ask Dr. Laundry

Washing White T-Shirts with Bleach

By Dr. Laundry April 30, 2009

Q. I have viewed your videos regarding Clorox® Regular-Bleach1, and they are very helpful. My 100% white cotton T-shirts instruct me to wash them in warm water with non-chlorine bleach. According to your video, you mention that “almost all cotton whites and most synthetic whites” can be bleached. My questions are as follows: What are examples of times when cotton whites and synthetic whites can’t be washed with bleach? I was once told that synthetics become gray if bleach is used, but this would be very difficult to determine using the bleachability test, as would doing the test on all cotton whites to try and find the infrequent instances where they fall outside the “almost all” category. Also, is it possible for color from the labels on the T-shirts to run due to the bleach?

A. Your questions really hit a nerve with me. I am not surprised that a lot of garment care labels inappropriately discourage washing using chlorine bleach, since I’ve also even seen it on white cotton T-shirts. I can tell you that after extensive testing and research, we have found that, when used as directed, liquid bleach like Clorox® Regular-Bleach1 can be safely used on all these garments. There are some items that should definitely not be bleached, and we list them on our label (wool, silk, mohair, leather, Spandex and nonfast colors).

Many clothing companies simply under-label all clothing to avoid any liabilities from laundry products and processes. You may be surprised to know that a large number of colored items can also be safely washed in Clorox® Regular-Bleach1. I recommend consumers do the quick Bleachability Test (2 tsp. Clorox® Regular-Bleach1 in 1/4 cup water; apply a drop on a hidden colored area like inside seam, hemline or cuff; wait 1 minute and then blot with towel); no color change means it is safe to use bleach on the item. Any color change could also show you the amount of change in color that likely will occur if you proceed with the liquid bleach usage. In addition, I have done testing on a wide range of items that showed there was no significant difference in fabric integrity between washing in detergent alone and detergent and 3/4 cup Clorox® Regular-Bleach1.

Now let’s finish your list of questions:
Examples of times that cotton and synthetic whites shouldn’t be washed together with bleach? The major issue with white synthetics is Spandex, which will react with the sodium hypochlorite active and yellow the item over time. The major synthetic used in most items is polyester, but there are no issues with using bleach on whites or colorfast colors. Polyester is harder to remove greasy/oily stains and soils from than cotton, which can mean you need to be more observant to catch and pretreat these stains before washing. Unremoved greasy stains can be “set” from dryer drying. The other issue is usually pilling from abrasion during wearing, washing and drying. Consider turning your items inside-out to help minimize this problem. Nylon has a reputation for graying, and it’s recommended that it be washed separately and not with bleach. This results from nylon’s affinity to attract any stray color/dye floating in the wash load, and essentially re-dying the item.

As for the labels: I wouldn’t expect any problem. If this was going to happen, it should have been visible “bleeding.” If you want further assurance, do a quick Bleachability test as described above on the label color.