Reusing Water Bottles

I was aware that you can't reuse water bottles for several times cause it is dangerous most especially if the bottle has been left in the car and exposed to heat. I received an email before that it was cancerous, so from the time I learned that I stopped doing that. I even shared this information to my parents and friends to warn them too.

However, a couple of days ago, my father told me that his attention was caught by his boss. The conversation went like this:

Boss: Ah, excuse me, Ramon, please come here.
Papa: Yes, boss?
Boss: I noticed you're reusing this bottled water.Don't reuse water bottles, it is deadly to your health. When you want to reuse a water bottle, check the triangular-shaped marking under the water bottle and look at the number written on it. If it says,"1", it is disposable, you can't reuse it. However, if it says,"5", then you can use it five times.
Papa: Oh, I didn't know that Sir. Thank you for telling me.

When Papa finished telling me the incident, I scolded my him saying, "Why? Didn't I tell you not to reuse water bottles? Okay now, so you listen okay, I'm aware reusing water bottles especially those that are kept in the car is cancerous. However, I didn't know about the triangular thingy. That made sense!"