SCP Foundation

…as any biological matter that has contact with SCP-XXXX will be then considered SCP-XXXX-1 from then on, until SCP-XXXX has been carefully removed from the subject. There are multiple monitoring devices within the security area, including, though not limited to motion detectors, cameras, and other such devices.

I would leave the basic generic stuff like "there are security cameras" out of the procedures unless it requires some deviation from what you'd expect to be the norm.

If you want more interesting procedure material, you could try replacing that clause I quoted with a better description of what removing SCP-XXXX entails.

It could be called a ‘stress relief ball’, as multiple subjects that came into contact with it claimed that it relieved their growing anxiety slightly.

I think that what gives it that term is that those objects are marketed under the name "stress ball", not whether it possesses actual stress-relieving properties.

Any biological matter coming into contact with the SCP immediately felt a growing paranoia, anxiety, and distrust of those around them. The longer they were in contact, the more the effects grew.

Any biological matter? Including sunflowers and hamburgers? That should probably be something like "living subjects", as an example of the sort of phrase you'd want.

Even under threats, their stance didn’t change, until ten minutes into original contact, that the paranoia was too much, and the ball couldn’t quell it.

The grammar here is both too informal (I wouldn't use "didn't") and hard to parse. This really needs to be straightened out into something more coherent.

Ten minutes seems to be the maximum amount of time the subject is willing to hold the object.

Instead of explaining what seems to be, explain what is. For example, you could say "No subject has ever held onto the object for longer than ten minutes."

and the aftermath resulted in them experiencing a level of mental retardation comparable of that to one who suffers from severe demensia, along with tier 3 burns They still have not recovered, and are in a vegetative state in St. Maria Hospital for the Mentally Handicapped in [DATA EXPUNGED], Mexico.

None of this medical information sounds right. You mean "dementia" and "third-degree burns". And I'm pretty sure that dementia is not a form of "mental retardation".

This was considered a curiosity until Dr. [DATA EXPUNGED] discovered all injuries that any of the subjects experienced were experienced by those within a hundred foot radius of the subject, and in extension SCP-XXXX. It is unknown however how the SCP selects what injury to inflict upon the user, or how the subject even manages to get harmed.

Wait, what? Do you mean that if they break their leg, so does everyone within a hundred feet? The next paragraphs imply that it picks the type of injury from among those that people nearby have experienced. Does that mean that if you just kept whoever picked it up 100ft away from anyone else, they'd be fine?

Oh yeah, and the Foundation uses metric.

They collected a sample of the rubber, which turned out to be of an unknown substance similar to a metal yet still like rubber, and would explain some of the paranoia those that held it experienced.

I don't understand this at all. It's rubber metal? And that explains paranoia?

Overall, this idea doesn't do much for me. It goes a little beyond the usual things that scare/hurt people around them — I kinda like the dynamic of a stress ball that makes you more anxious, building your dependence on it — but you don't do much with that. It falls flat in execution, like trying to bounce a rubber ball made of metal.