No, but it's also completely incompatible with the stuff in your car now and it's very expensive.
As to the fluids that don't require you to flush the brake system two or three times when changing over, try a good brand-name DOT 4 fluid.
If your brake fluid is hygroscopic then it means that is will absorb water/moisture from the air and it can effect your boiling point and your brakes may fail at high speeds.
Yes it readily absorbs moisture.
If the synthetic fluid is silicone based, yes. If it is a dot 3or 4 type, no.
purple
Dot 5
DOT 5
DOT 5 is silicon based and will not absorb moisture.
Brake fluid must be changed every two years at most. Since it is hygroscopic--that is, it absorbs moisture/water over time. with our tropical climate, this problem is exacerbated. Fresh brake fluid helps resist brake fade and give better brake feel and modulation.
DOT 3, DOT 4 or DOT 5.1 (but NOT DOT 5, which is silicone brake fluid) can be used in your car.
yes,,,, all brake fluid is synthetic. EXCEPT Dot 5 which you CANNOT mix only because it is silicone based.
No, the fluid cannot absorb water but you can get water in your brake system and that would be bad. --Most brake fluids used today are glycol-ether based. Glycol-ether brake fluids are hygroscopic (water loving), which means they absorb moisture from the atmosphere under normal humidity levels. Racing brake fluid may be synthetic and not have this problem, but in the everyday world, brake fluid does absorb water.
DOT 5 is a silicone brake fluid and not compatible with the original fluid or components. IF the system is contaminated, take it SOON to a reputable shop for help.