These are full 5L tanks of all the secret liquids (in their pure 100% form) that are currently available in People Playground, including:
--- One full tank of 100% Tritium (taken from Atom Bombs) ---
[Effect: Makes humans radioactive and glow green. It also makes them have somewhat of a panic attack while slowly killing them.]
(Side note: No matter how much you inject into Androids, they seem to be completely immune to Tritium and it only makes them glow green.)
--- One full tank of 100% Exotic Liquid (50% Tritium, 50% Water Breathing Serum) ---
[Effect: Makes random blue sparks appear around humans, as well as electrifying and burning them a little bit. Also, whatever is filled with Exotic Liquid (be it a human, a container, or something else), will constantly fluctuate in temperatures of around -12 °C to +4 °C. The reason for this behavior is currently unknown.]
(Side note: By connecting a wire to whatever is filled with Exotic Liquid, you can generate small amounts of electricity. This even works with humans that have Exotic Liquid inside of them.)
--- One full tank of 100% Osteomorphosis Agent (50% Mending Serum, 50% Acid) ---
[Effect: Has a very similiar effect to Acid and Gorse Blood, with the only seeming difference being that it takes twice as long (~7 seconds vs. ~14 seconds) for a full tank to eat away the flesh, dismember and kill a human. This may be because this liquid is bugged in the current version, since on the (unofficial) wiki, it states that it should leave behind a skeleton with all limbs attached and all flesh eaten away, not a dismembered skeleton. But you can experiment with it for yourself to come to your own conclusions.]
(Side note: The seemingly intended effect does actually work on Gorses, making them lose their flesh and only leaving their non-dismembered skeleton behind, with all bones attached.)
EDIT: I found a way to make Osteomorphosis Agent work on humans! The way you do it is you have to set the Osteomorphosis Agent container to "drain" and then just spill a bunch of the liquid onto a human, making him lose all of his flesh but keeping his bones attached. This way you can finally make a cool skeleton! Unfortunately, this doesn't work on Androids, since they have armor protecting them.
--- One full tank of 100% Immortality Serum (50% Mending Serum, 50% Tritium) ---
[Effect: Makes humans pretty much immune to almost all damage you deal to them. While still killable, humans will become way harder to kill, but the effect of the Immortality Serum stops when a human doesn't have any more blood in his system or in his head, since the Immortality Serum won't have anything to circulate through.]
(Side note: For some reason, Immortality Serum makes the body parts of Androids explode at random time intervals and doesn't make them immortal.)
EDIT: Ok, I found out why Immortality Serum gives humans "panic attacks". It's not that they get panic attacks, it's just that they lose balance if you inject it into only one of their limbs, making one limb too strong and have too much integrity. The fluid itself spreads like normally through their bloodstream, but the integrity of the limbs only increases on which body parts you injected the immortality serum into.
For example, if you only inject the Immortality Serum into the lower leg, then only the lower leg will increase it's integrity, but the effect of "immortality" will spread across the whole body. Thus, only the integrity of the lower leg increases, making the human flop around and lose balance, but the whole body will still become almost immune to most damage. The fact that integrity doesn't increase across all body parts equally is most likely a bug, and there's nothing I can do about it, so we'll have to wait for the developer (Zooi) to fix it.
However, there are 2 very simple solutions to this problem:
Solution number 1: Only inject the Immortality Serum into the head or the upper torso (or both), this will mostly prevent humans from being floppy and losing balance. These are the only two body parts that can be injected into without the humans losing balance.
Or solution number 2: Inject an equal amount of Immortality Serum into all 14 body parts, since this will equally increase integrity across all body parts. You can do this by either pausing time, connecting a blood vessel wire between the container and every single body part and then unpausing, or you can just inject 14 containers into one human, one container for every body part.