Do PPR pipes resist to acid and alkaline?

Do PPR pipes resist to acid and alkaline?
The acidity and alkaline of our drinking water is expressed in  in pH in chemistry, pH = 7 to neutral, pH < 7 as acidity, pH > 7 is alkaline, One simple method to measure the PH degree of acid and alkali is to use  pH indicator paper. You can test the PH by yourself to experience of drinking water PH value if you have that paper in hand.  

The world health organization did not mention clear standard for the drinking water quality. Our GB5749 drinking water hygiene pH indicator is in 6.5 to 8.5; GB17324 bottled drinking water pH indicator is in 5.0 to 7.0. These indicators and the developed countries, in line with the standard of water can be rest assured to drink.

PP plastics are chemically inert, so Ppr pipe is resistant to general acidic medium.

Due to the chemical inertness of PPR pipe, it has a strong resistance to alcohol, acid, alkali and low boiling point hydrocarbon solvent. At indoor temperature, ppr materials are difficult to be dissolved in most organic solvents. And when in Water-based reagent like acid or alkali, the possibility of environmental stress cracking damage is very small. but when with chlorinated organic compounds, strong oxidizer, liquid hydrocarbon contact, it is easy to cause surface crack or swelling, because nonpolar compounds can be easily absorbed by polypropylene. 

PPR pipes can resist general acidic medium, but not strong acid and strong base. 

Therefore, if ppr pipes are for general residential use, no need to worry about the resistance issue.