White powder on Lithium ion batteries

[Zev_7]

I have two laptops, one HP laptop that i bought in 2018-2019 that has a bad battery after a year of usage and a 2010 Macbook that also has a bad battery 
Both laptop batteries seem to have this white powder on them and i have no idea where it came from? 
On the HP, the powder was underneath the battery
On the macbook, the powder was on the top of the battery

Is this safe? And what should i do? As for replacing them im not sure if id be able to, as hp is charging me $152 for the battery alone and no other third parties sell it. The macbook has third party sellers for the battery, but I'd rather fix the newer laptop than use the 2010 one.

[Stu_Bear]

Lithium hexafluorophosphate...i'd not play with it...it's toxic.

[Zev_7]

13 minutes ago, Stu_Bear said:

Lithium hexafluorophosphate...i'd not play with it...it's toxic.

I removed it with my hand from the HP laptop and didn't wash my hands last night. 

Washed my hands this evening though, so any side effects of doing so? 

[Stu_Bear]

You'll be fine...just don't make a habit of it.