A) Burning and smell:Human hair will be ash and smell foul, when burning, the human hair will show white smoke. While synthetic hair will be a sticky ball after burning and will show black smoke.

B) Human hair feels like kind of cool feeling.

C) Moreover, human hair may have very few gray hairs and split ends. It is normal and not a quality problem.  

Q2: Why my brazilian hair extensions get tangled?

It must due to dryness, oil & dirt build up, salt water, chlorine and not combing (wide tooth comb) outyour hair daily.

Suggestions:

A) Make sure to wash & condition your hair at least once a week, twice a week is better. 

B) Use hydrating drops or consult your stylist for more help.

Q3: Can they be straightened, curled ?

Yes,you could use hair straightener or hair curler to style.However, don't do it too frequently, or the heat will make the hair easily get dry and tangled.

Q4. What type of hair care products should I use?

Treat this hair just as if it was your own hair.

1.Use good quality shampoo and hair conditioner to care the hair. It's important to keep the hair soft and shiny.

2.You could use gel or spray styling products to keep the hair style.

3.Olive oil will be a good choice to keep the hair healthy.