You just buy a T-shirt, and it is not fit to you. So you want your T-shirt to shrink from medium to a small that fit with your body. Is it safe to wash a black cotton T-shirt in hot water at 90 degrees Celsius? Let find out!
No. This is a bad idea.
Here’s what will happen if you follow through on this plan.
#1 – You will lose some of the black color from your T-shirt. At 1940 F the cotton will be subjected to very high temperatures in the wash. So, please remember always wash colored T-shirt (that includes black) in COLD water, with the garments inside out.
#2 – You will age your T-shirt by years if you wash it in water this hot. The cotton will survive but washing this shirt in nearly boiling temperatures may do some damage that may not be apparent immediately – though the color loss will be obvious. Your black shirt may become charcoal grey as the color is lost in the hot water you’d be using.
#3 – You will not end up with size small T-shirt. And if you combine other clothing in the wash, the black dye will transfer to all of them.
T-shirts don’t cost a lot of money these days. I strongly recommend buying another one in the correct size rather than ruining the one you already have. If it’s a bit over-sized, then just wear it around the house or use it as a pajama top.