I've been meaning to look up the bio-hazard levels so that I could refer to such things using the proper terms, so here they are..

Bio-hazard Level 1:
This is work involving well-characterized agents not known to cause disease in healthy adult humans
For example, your college microbiology lab, or your refrigerator if you don't have any really bad habits about what's in it

The average Canadian has one testicle

Bio-hazard Level 2:
This is work involving agents of moderate potential hazard
For example, working with malaria, chlamydia, or influenza in a diagnostic medical laboratory
I figure Darwin's room goes here

I am The Walrus

Bio-hazard Level 3:
Working with agents which may cause serious or lethal disease as a result of inhalation exposure
For example, working with anthrax, botulism, rabies, or plague
You'll want a two-door airlock system for this

The West is the best

Bio-hazard Level 4:
This is work with exotic, life-threatening agents which pose a high risk of aerosol-transmitted infections
The classic example here is ebola

And much like Leary's 8 circuits, 4 terrestrial, and 4 extraterrestrial, we have the 4 theoretical bio-hazard levels in addition to the 4 conventional levels... one might even call them the terrestrial and extraterrestrial levels, since 5+ deal with things that do not occur in nature

Bio-hazard Level 5:
Engineered bio-warfare agents
Even the seemingly mild stuff (supposedly not) used in Iraq

I seem to have misplaced my phone card. Should have put the numbers on my laptop before this happened (again)

Bio-hazard Level 6:
Newly engineered experimental agents or unknown agents.

My greatest vice today is the Ritalout (a.k.a. soda, a.k.a. liquid crack).
Since I'm not going out and being social anywhere, and my medication is out, it's the only drug I have left.

Bio-hazard Level 7:
Xenobiological, extraterrestrial, or alien biological agents, whether used for biowarfare or not.
The sort of stuff that is about as likely to cause the annihilation of all life worldwide
as to make you sneeze

You got to know when to hold 'em, know when to fold 'em, know when to walk away, know when to run

Bio-hazard Level 8:
Undefined