Awesome.
Now, for the part how it works, to spare you the googling, white it's technically logarithm equation, it's explained rather easily:
The number after "OD" is the amount of places you move the decimal point to the left.
Suppose your 1W 980nm laser. That's 1000mW.
OD3 goggles will reduce that by 3 decimal points, or 1.0 mW.
You will notice that is one-fifth of the limit for safe optical exposure for
visible lasers. Invisible lasers have even higher threshold because they do not "flash blind" the optical nerves (primary concern with visible lasers, i.e. pilots and laser accidents), you have to get high enough in power to actually cause thermal and chemical damage.
You suggest OD8+.
Even IF you manage to find them without having to sell a kidney, you may notice that reducing 1000mW to 0.00001mW is totally an overkill.
I hope you can see the logic behind all this and when you do hand out safety advices to members (which is commendable!), I hope you do it accurately and professionally.
Judging by your nickname, you're well versed in computer hardware.
Your laser safety advice is equal to reccomending liquid nitrogen cooling for a 77W TDP processor.
Or in other terms, reccomending GFX Titan for GTA San Andreas.