Technically, bleach by itself isn't as worrisome as it is when it is combined with other chemicals. If inhaled as a gas, bleach fumes cause breathing problems, nausea, and even loss of consciousness and headaches. If you already suffer from asthma or chronic bronchitis (or any other lung related disorders) you need to really avoid bleach products because it can aggravate your condition.
For example, using bleach with any types of products containing ammonia, like glass cleaners, it will form chlorine gas. Believe it or not, chlorine gas is so hazardous to your health that it was used as a weapon in chemical warfare during both WWI & WWII. It irritates the linings of your eyes, throat, and your lungs; and because it is heavier than oxygen, it can accumulate at lower levels.
Bleach is also a heavy skin irritant. You may develop skin redness, rashes, and even sensitivity after coming into contact with bleach - such as a swimming pool.
So what can you use as a bleach alternative? Try this recipe:
1 cup hydrogen peroxide
3 tablespoons lemon juice
15 cups of water
Mix ingredients together and use as you would a commercial bleach product. Store in a cool, dark place. The approximate shelf life is 3-6 months.
Cited Sources: http://ezinearticles.com/?The-Pros-and-Cons-of-Using-Bleach&id=3571205; Book: Natural Cleaning For Your Home by Casey Kellar