Item #: SCP-099-DE
Object Class: Euclid
Special Containment Procedures: SCP-099-DE comprises the whole Sector 8 on Level 2 of Site-DE4. All accesses save for the airlock are to be concreted over gas-tight and to be correctly sealed, including all connections of the air conditioning, water supply, maintenance shafts, cable tunnels etc. The media- and power-supply are cut off. SCP-099-DE is to be checked for leaks on a daily basis.
The airlock has two chambers (one on SCP-099-DE's and one on to entrance areas side) and is vacuum-proof. If a person enters one of the chambers, a vacuum is created in both chambers, so that the atmosphere of both chambers can not mix. In their frame there are ultraviolet lamps with a wavelength of ≤ 290 nm and a total output of 2 kW, of which must never be less than 70% in operation. Defective illuminants are to be replaced immediately. The inside of the airlock is coated ultraviolet-resistant, the observation windows are equipped with strong UV- and IR-filters. The normal illumination of the airlock is to be equipped with filters for infrared light with wavelengths over 1.1 µm, which are to be checked for damages regularly.
Personnel entering SCP-099-DE must be wearing a gas-tight vacuum-proof protective suit with independent air supply, and is to be equipped with infrared vision googles with infrared spotlight, a light source for visible light with an infrared filter and a UV-laser projector with a power output of ≥ 0,7 kW and a wavelength of ≤ 250 nm, which must not be strong enough to damage the equipment and premises. In case such a laser is equipped, all those present must be wearing laser protection googles. All this is optional for D-class personnel.
Description: SCP-099-DE is an unknown gas which has homogeneous intermingled with the air in Sector 8. An accurate chemical analysis of the gas has so far not been possible. The density of the air-gas mixture amounts to 1.7 kg/m³ at 20°C. Chemical reactions tough have resulted in a pressure drop in the whole sector to 0.9 bar (absolute). It disintegrates under UV-light with a wavelength of ≤ 320 nm into air and black flakes of soot. This flakes are composed of [DATA EXPUNGED].
The interior of Sector 8 shows a normal degree of decay for the duration of lock-down, though it seems that big debris like fallen down ceiling panels, are put to the sides.
SCP-099-DE-1 is the entirety of meanwhile 38 entities, that are completely transparent for visible and ultraviolet light (and therewith “invisible”), and seem to be composed entirely of SCP-099-DE. Under infrared light with a wavelength of ≥ 1,6 µm they are becoming visible as a translucent “shadow”. They are of roughly human shape with relatively long arms without hands or fingers. Like SCP-099-DE they are sensitive to UV-light.
Normally they are peaceful and avoid personnel of the Foundation. Though if they are directly illumined by infrared light, they are stopping and turn towards the nearest source of infrared light. Should they be illumined for longer than 20 seconds, they start moving towards the light source. As soon as they are within 220 cm to the light-source, the attack the light-source/its carrier. Because of their gaseous form they are initially harmless, though the ends of their arms start forming three “claws”, which gaining density, until they resublimate into solid state and start ripping open the protective suit of their victim. They then enter the protective suit and through the lungs are getting into the circulatory system. [DATA EXPUNGED] the victim dies from anoxia. After approximately 5 minutes the corpse starts disintegrating into black soot, which in the end dissolve. Breathing of SCP-099-DE over the period of 3 hours or more are showing the same result.
It takes SCP-099-DE-1 circa 1-2 minutes from the start of the attack till resublimation of the claws. During this time they can be “injured” with a UV-laser projector. Cutting off the head or extremities has proven to be most effective. Damages to the torso are being “healed” quickly by the surrounding SCP-099-DE. Severed extremitys disintegrate into soot; defeated entities will try to flee. Injuries are not permanent, extremities are regrowing or growing onto the body again, the soot disintegrates to SCP-099-DE. If a fleeing or peaceful entity is being attacked by SCP-personnel, close instances of SCP-099-DE-1 are gathering nearby the personnel. If they are further provoked, they are attacking as a group, which usually ends deadly for the personnel. Though they spare those who shut off their infrared lights, are not equipped with a laser projector and are signalizing peacefulness.
If instead of the infrared equipment only light sourced with visible light are used, the entities do not react to personnel, even if these are randomly lasering around. If an attack has begun though, it cannot be stopped by switching of the infrared light.
Addendum 1: The exact origin of SCP-099-DE is unknown. It was found after the lock-down of Site-DE4 was triggered, when shortly after the morning break the disintegrated corpses of multiple employees have been found in the break room of Sector 8. After lock-down, the contact to Sector 8 broke off gradually and in the end stopped completely. 5 days after the incident, the airlock was set up and Search Team-DE4-𝔅 was sent into the sector to find an explanation and to search for the corpses.