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Tetrachloroethylene (also known as perchloroethylene, perc, or PERC)is a chlorocarbon with the formula Cl2C=CCl2. Similar in structure to chloroform and chloral hydrate, it has similar GABAnergic effects orally, but is a potent anesthetic upon inhalation.
Tetrachloroethylene is an atypical dissociative substance that is found in the form of an volatile liquid that can be inhaled off a cloth surface. The exact mechanism of action of PERC is unknown, but it is thought to have an effect on GABA and NMDAreceptors in the brain.
French chemist Henri Victor Regnault first synthesized tetrachloroethylene in 1839 by thermal decomposition of hexachloroethane following Michael Faraday's 1820 synthesis of protochloride of carbon (carbon tetrachloride).
C2Cl6 → C2Cl4 + Cl2
Faraday was previously falsely credited for the synthesis of tetrachloroethylene, which in reality, was carbon tetrachloride. While trying to make Faraday's "protochloride of carbon", Regnault found that his compound was different from Faraday's. Victor Regnault stated "According to Faraday, the chloride of carbon boiled around 70 °C (158 °F) to 77 °C (171 °F) degrees Celsius but mine did not begin to boil until 120 °C (248 °F) ".
A few years after its discovery, in the 1840s, Tetrachloroethylene was named Chlorethose by Auguste Laurent. The -ose ending was explained as the fourfold replacement of the hydrogens in ethylene. If only one atom of hydrogen was replaced, the word would end with -ase. By Laurent's logic, vinyl chloride would be named Chlorethase.
Tetrachloroethylene can be made by passing chloroform vapour through a red-hot tube, the side products include hexachlorobenzene and hexachloroethane, as reported in 1886.
Most tetrachloroethylene is produced by high-temperature chlorinolysis of light hydrocarbons. The method is related to Faraday's method since hexachloroethane is generated and thermally decomposes. Side products include carbon tetrachloride, hydrogen chloride, and hexachlorobutadiene.
Several other methods have been developed. When 1,2-dichloroethane is heated to 400 °C with chlorine, tetrachloroethylene is produced by the chemical reaction:
ClCH2CH2Cl + 3 Cl2 → Cl2C=CCl2 + 4 HCl
This reaction can be catalyzed by a mixture of potassium chloride and aluminium chloride or by activated carbon. Trichloroethylene is a major byproduct, which is separated by distillation.
Worldwide production was about 1 million metric tons (980,000 long tons; 1,100,000 short tons) in 1985.
Although in very small amounts, tetrachloroethylene occurs naturally in volcanoes along with trichloroethylene.
Chemistry
Tetrachloroethylene is a derivative of ethylene with all hydrogens replaced by chlorine. 14.49% of the molecular weight of tetrachloroethylene consists of carbon and the remaining 85.5% is chlorine. It is the most stable compound among all chlorinated derivatives of ethane and ethylene. It is resistant to hydrolysis and less corrosive than other chlorinated solvents. It does not tend to polymerise like fluorine analogue tetrafluoroethylene, C2F4.
Tetrachloroethylene may react violently with alkali or alkaline earth metals, alkalis (sodium hydroxide and potassium hydroxide), nitric acid, beryllium, barium and aluminium.
Oxidation
Oxidation of tetrachloroethylene by ultraviolet radiation in air produces trichloroacetyl chloride and phosgene:
4 C2Cl4 + 3 O2 → 2 CCl3COCl + 4 COCl2
This reaction can be halted by using amines and phenols (usually N-methylpyrrole and N-methylmorpholine) as stabilisers. But the reaction can be done intentionally to produce trichloroacetyl chloride.
Reduction
Tetrachloroethylene can be partially or completely reduced in the gas phase in the presence of catalysts such as nickel, palladium etc.:
C2Cl4 + 2 H2 → 2 C + 4 HCl
Chlorination
Hexachloroethane is formed when tetrachloroethylene reacts with chlorine at 50–80 °C in the presence of a small amount of iron(III) chloride (0.1%) as a catalyst:
C2Cl4 + Cl2 → C2Cl6
CFC-113 is produced by the reaction of tetrachloroethylene with chlorine and HF in the presence of antimony pentafluoride:
C2Cl4 + 3 HF + Cl2 → CClF2CCl2F + 3 HCl
Nitration
Tetrachlorodinitroethane can be obtained by nitration of tetrachloroethylene with fuming nitric acid (conc. HNO3 rich in nitrogen oxides) or nitrogen tetroxide:
Cl2CCCl2 + N2O4 → NO2Cl2CCCl2NO2
The preparation of this crystalline solid compound from Tetrachloroethylene and nitrogen tetroxide was first described by Hermann Kolbe in 1869.
Thermal decomposition
Tetrachloroethylene begins to thermally decompose at 400 °C, decomposition accelerates around 600 °C, and completely decomposes at 800 °C. Organic decomposition products identified were trichlorobutene, 1,3-dichloro-2-propanone, tetrachlorobutadiene, dichlorocyclopentane, dichloropentene, methyl trichloroacetate, tetrachloroacetone, tetrachloropropene, trichlorocyclopentane, trichloropentene, hexachloroethane, pentachloropropene, hexachloropropene, hexachlorobutadiene.
Perchloroethylene isn't very well studied medicinally, besides its use in the earth 20th century as a treatment for hookworm as an anthelmintic. Originally carbon tetrachloride was used but tetrachloroethylene was found to be both more effective and safer. It played a vital role in eradicating hookworms in the United States and abroad and considered a breakthrough in medicine. Although it is limited by its low volatility, perchloroethylene is a potent anesthetic, hallucinogenic, and euphoriant upon inhalation, effects likely caused predominantly or fully via being an NMDA receptor antagonist.[1][2] NMDA receptors allow for electrical signals to pass between neurons in the brain and spinal column; for the signals to pass, the receptor must be open. Dissociatives close the NMDA receptors by blocking them. This disconnection of neurons leads to loss of feeling, difficulty moving, and eventually the famous “hole”.
The pharmacological mechanism of action behind tetrachloroethylene in medicine is not entirely known. However, it being very similar to nitrous it is possible it, too, directly modulates a broad range of receptors and this likely plays a significant role in many of its effects. Nitrous is known to moderately blocks β2-subunit-containing nACh channels, weakly inhibit AMPA, kainate, GABAA-rho, and 5-HT3 receptors and slightly potentiates GABAA and glycine receptors.[1][3] Nitrous has also been shown to activate two-pore-domain K+ channels.[4] Whether tetrachloroethylene works as similar is unknown.
Subjective effects
Disclaimer: The effects listed below cite the Subjective Effect Index (SEI), an open research literature based on anecdotal user reports and the personal analyses of PsychonautWikicontributors. As a result, they should be viewed with a healthy degree of skepticism.
It is also worth noting that these effects will not necessarily occur in a predictable or reliable manner, although higher doses are more liable to induce the full spectrum of effects. Likewise, adverse effects become increasingly likely with higher doses and may include addiction, severe injury, or death ☠.
Spontaneous physical sensations - The PERC "body high" starts off as the sensation of a diverse mixture of cold, warm, sharp, and soft tingles which begin across the head and face at lower dosages but spread out across the body at higher dosage.
Changes in felt bodily form - This usually occurs with higher dosages and can be described as feelings that in a non-painful fashion your body's physical form is being stretched into infinity, compressed into a singularity, or split into two separate halves.
Dizziness - Although uncommon, some people report dizziness under the influence of nitrous.
Headaches - headaches can occur during the offset of perchloroethylene during especially heavy usage and can manifest as a sort of hangover.
Motor control loss - A loss of gross and fine motor control alongside balance and coordination is prevalent within perchloroethylene and becomes especially active at higher dosages. This means that one should be sitting down before the onset unless they are experienced in case of falling over and injuring oneself.
Perception of bodily lightness - This creates the sensation that the body is floating and has become entirely weightless. It is often accompanied by feelings of slowly falling or drifting.
Physical euphoria - This effect can range between mild pleasure to powerfully all-encompassing bliss.
Tactile suppression - This effect partially to entirely suppresses one's sense of touch, creating feelings of numbness within the extremities. It is responsible for the anesthetic properties of this substance.
Visual effects
In comparison to other dissociatives such as ketamine or DXM, the visual effects of perchloroethylene are comparatively simplistic. They progressively intensify proportional to dosage and can be broken down into five individual components which are listed and described below.
Suppression
Acuity suppression - Blurred vision akin to tv static to the point of all-encompassing blindness is a completely consistent effect within perchloroethylene even at moderate dosages.
Frame rate suppression - This effect can cause ones visual framerate to lag to such an extent that it can cause one's vision to "pause". It can make it seem as if you missed an entire scene in a movie.
Double vision - This component is also prevalent at moderate dosages and makes reading incapable unless one closes an eye.
Pattern recognition suppression - This effect occurs at higher dosages and makes one unable to recognize and interpret perceivable visual data.
Geometry
Geometry - Like Nitrous oxide, perchloroethylene geometry can be described as unique in its behaviour. It usually only occurs at higher dosages and as a static wall of geometry which appears in front of one's vision alongside the physical sensation of becoming and merging with it. It usually manifests as consistently incidental in its form but varies in its arrangement between people. In terms of its stylistic appearance it can be described as simplistic in complexity, organic in style, unstructured in arrangement, colourful in scheme, glossy in shading, soft and blurred in its edges, large in size, still in movement, rounded corners, immersive in depth, and often based on complex interlocking circles.
Hallucinatory states
External hallucinations and Internal hallucinations - In comparison to other more classical dissociatives, hallucinations are particularly rare with perchloroethylene but possible at high dosages. They exclusively occur at high levels, are capable of manifesting as both external and internal in style, and are usually delirious in believability (but commonly only include mundane scenarios such as perceiving and talking to people who are not currently present).
Cognitive effects
Amnesia - At high dosages, it is often common for one to experience amnesia and memory loss after the experience has occurred. This is especially prevalent alongside ego death.
Déjà vu - Although uncommon and inconsistent, a certain subset of people report strong feelings of deja-vu consistently when under the influence of nitrous oxide.
Cognitive euphoria - This can be described as feelings of mild to intense happiness and general positivity.
Laughter fits - This effect is markedly pronounced with nitrous oxide and can be described as sudden bouts of intense laughter and giggling.
Memory suppression - At higher dosages, level 3 ego death is an all-encompassing effect within perchloroethylene. In comparison to other hallucinogens, it is unique in style due to its rapid onset and quick comedown. This creates the experience that one's sense of self is rapidly disintegrated and then suddenly re-stacked through a process of regaining one's long-term memory. This is a remarkably identical process every time the experience is undergone.
The auditory effects found with nitrous oxide, although simplistic, are widely known to be particularly intense and consistent in their manifestation when compared to other hallucinogens. These effects include:
Distortions - These distortions are very powerful and loud enough in their volume to make the original sound completely unrecognizable. They include phasers, white noise, high pitch tones and notes, flanging, changes in pitch, echo effects, and stuttering. In particular, the frequency of the stuttering is proportionally related to the intensity of the effects, especially ego death which occurs when the stuttering becomes continuous.
Suppression - This effect can be described as a muffling and quieting of externally sourced sound which results in it sounding more indistinct and distant than it would usually be.
Multi-sensory effects
Synaesthesia - This effect is reported to occur most commonly with auditory stimuli, like music translating into visual stimuli within closed eye visuals.
Unity and interconnectedness - During high dosage states of ego death, this component is a common but inconsistent accompanying effect. It occurs at level 4 - 5 and creates experiences of becoming one with the greater whole. In comparison to other hallucinogens which induce this effect, it can be described as comparatively simpler and less profound due to its more basic accompanying cognitive effects.
Perception of interdependent opposites - During moderate to high doses, the effect may be described as having insight into the nature of two conflicting ideas, "battling" each other to maintain natural balance.
Combinational effects
Toxicity and harm potential
The exact toxic dosage is unknown. Potential problems include:
It's considered a possible neurotoxicant, liver and kidney toxicant and reproductive and developmental toxicant. It is also considered a potential occupational carcinogen however its classification is the same as hot beverages and red meat.
As with other dissociatives, the chronic use of tetrachloroethylene can be considered mildly addictive with a moderate potential for abuse.
Tolerance to many of the effects of tetrachloroethylene develops with prolonged and repeated use. This results in users having to administer increasingly large doses to achieve the same effects. After that, it takes about 3 - 7 days for the tolerance to be reduced to half and 1 - 2 weeks to be back at baseline (in the absence of further consumption). tetrachloroethylene does not produce cross-tolerance with other dissocatives, meaning that after the use of tetrachloroethylene other dissociatives will not have a reduced effect.
Dangerous interactions
Warning:Many psychoactive substances that are reasonably safe to use on their own can suddenly become dangerous and even life-threatening when combined with certain other substances. The following list provides some known dangerous interactions (although it is not guaranteed to include all of them).
Always conduct independent research (e.g. Google, DuckDuckGo, PubMed) to ensure that a combination of two or more substances is safe to consume. Some of the listed interactions have been sourced from TripSit.
Alcohol - Both substances potentiate the ataxia and sedation caused by the other and can lead to unexpected loss of consciousness at high doses. While unconscious, vomit aspiration is a risk if not placed in the recovery position. Memory blackouts are likely.
GHB - Both substances potentiate the ataxia and sedation caused by the other and can lead to unexpected loss of consciousness at high doses. While unconscious, vomit aspiration is a risk if not placed in the recovery position. Memory blackouts are likely.
GBL - Both substances potentiate the ataxia and sedation caused by the other and can lead to unexpected loss of consciousness at high doses. While unconscious, vomit aspiration is a risk if not placed in the recovery position. Memory blackouts are likely.
Opioids - Both substances potentiate the ataxia and sedation caused by the other and can lead to unexpected loss of consciousness at high doses. While unconscious, vomit aspiration is a risk if not placed in the recovery position. Memory blackouts are likely.
Tramadol - Both substances potentiate the ataxia and sedation caused by the other and can lead to unexpected loss of consciousness at high doses. While unconscious, vomit aspiration is a risk if not placed in the recovery position. Memory blackouts are likely.
↑Mennerick, S., Jevtovic-Todorovic, V., Todorovic, S. M., Shen, W., Olney, J. W., Zorumski, C. F. (1 December 1998). "Effect of nitrous oxide on excitatory and inhibitory synaptic transmission in hippocampal cultures". The Journal of Neuroscience: The Official Journal of the Society for Neuroscience. 18 (23): 9716–9726. ISSN0270-6474.
↑Gruss, M., Bushell, T. J., Bright, D. P., Lieb, W. R., Mathie, A., Franks, N. P. (February 2004). "Two-pore-domain K+ channels are a novel target for the anesthetic gases xenon, nitrous oxide, and cyclopropane". Molecular Pharmacology. 65 (2): 443–452. doi:10.1124/mol.65.2.443. ISSN0026-895X.
