Difference between PLA and ABS

Is there way to tell the difference between ABS and PLA?
I have received some filament,without an indication as what it is and I am trying to decide if it is PLA or ABS
Regards

Chuck a piece of the filament in acetone. If it is ABS it will slowly dissolve. If it is PLA it will be more or less unaffected.

Or burn it and carefully whiff it. Dont inhale too much. The one that smells more organic is the PLA.

Also have heard PLA is more shiny, but that doesnt seem true.(or indicative, anyway)

If it's at all translucent, it's very likely PLA. There are some translucent ABS filaments out there, but they are generally pretty rare. If it's a solid color, it could be either.

I would try to extrude it at 180 C with relatively high feed rate, like 70+ mm/min.

If it does not come out at all, or it comes out but there are some choke ups, irregularity, discontinuation, then it would be most likely ABS.

Also, if the hobbed bolt (if your extruder uses a hobbed bolt) digs into the filament, then it's very much likely ABS - all PLA filaments I've used were pretty hard, that they did not allow the teeth of the hobbed bolt sink in, it rather stopped the extruder gear.

On the other hands, all ABS i've used were pretty soft and easily allowed the hobbed bolt to dig into them.

Well, the very first filament I ever used was ABS (black) and I was actually able to print with it at 180 C successfully to some degree (and that caused me to believe it was PLA until I almost used the entire 1kg spool). So, I don't think this temperature/extrusion test is 100% reliable.

i always do a burn test...

You could try snapping about 1 inch from the end, if it's ABS, it will become white from the stress of you bending it. If it's PLA, it will snap instead.

Put it in hot water (recently boiled). ABS will have no effect, PLA will become like rubber / jelly.

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I don't think the burning test is advisable - ABS releases hydrogen cyanide gas when burnt hot enough, and it's really worth avoiding whiffing that...

Ye i would just put it in bioling water and look if it becomes flexible like Nophead said,
most easy and safe way to test it.

Thanks guys,,
I think the easiest test is the boiling water, the PLA goes soft and the ABS remains hard, Its simple.