UL divides the wiring us←'>"ed for voice and data ✔$'>systems into "communic♣∑∑ation wiring and cables"，Abbreviated as CM. This catεφegory provides multiple safety le×∑‍vels for specific applications t≤'¶o verify the quality ✔ of cable jackets, as follows:

CMP: Fill grade communication©↓$• cable, which is the highest c≥←able safety level. It has perfect÷  flame retardant ability and emits ≥≠φ♠very low smoke and toxins. A≠φ‌ccording to UL definition, a♦✘©≥ bundle of CMP cables in Dongguanφ∑®₹ must self extinguish within ↓§€5 meters of the combustion spreading u←€♦‍nder the condition of for≈≥ced dense combustion by the ‍★•​fan. CMP cables use Teflo b₩≥₽×ased chemicals to pre∏↑↔↕vent combustion diffusion and < minimize the emission of smoke and ↔≤toxins. Compared to cabl₩≤β↑es with lower UL ratings, this ‍εincreases the cost significant☆™©ly. CMP grade cables are used i←☆n buildings where cables are →γ£←laid inside the ventilation and±≤ § return air ducts. In t↔&he event of a fire, the bui✔σεlding will not be filled with a large↕σ amount of smoke or hδ₩azardous toxins emitted by cables. This☆   type of return air mes→ >h is widely used in the United States,✘¶ but is less commonly used in→₹ other parts of the world. C®βMP grade cables mustλ§→ undergo strict combustion testing: U★‍∏φL910- "Flame Propagation an>‌♠d Smoke Density Test"

CMR: Trunk level com₹§munication cable. This is theα✘↕∑ second ranked cable, which has α←perfect flame retardant abili ₽ty, but there is no testing fo"∑γr the emitted smoke and toxins. Eε$xcept for CMP and cables,α×ε CMR cables and all other communi£ γcation cables use halide based ₽© chemicals such as chlorine to prevent ‌αcombustion diffusion. According¥' → to the definition, under the condi★≠€tion of forced combustion of the ↕↓₽£fan, a bundle of CMR cables must self eΩ≤xtinguish within 5 meters‌∞ of the spread of combustion. The™€π↑ CMR cable jacket is usually → €made of a certain type of PVC, which e≈φ&mits chlorine gas in th✘✔>e combustion chamber, which exhausδ↔✘♣ts oxygen in the air an ‍γd extinguishes the fl≤λ→ame. CMR grade cables arφ✔e widely used in trunk ap÷$plications where ventilation ≠‍φ£systems are physically separated fr±≈♠om wiring systems. This is very common↓★↕ in Asia and Australia. C₽☆←✔MR grade cables must undergo intensive"₹♣₩ flame testing: UL16δ≥66- "Flame Propagation Heigh•♦÷t Test for Cables Installed Verticallyφ≈₹ Through"

Low Smoke Zero HaloΩ​∞gen (LSZH): Another saf←€ety level used in the wiring industβ→♥ry is Low Smoke Zero Halogen (×₽LSZH) cables. This security₽δ level is defined by ISO/IEC☆÷★ standards and is widely£∏± used in Europe. LSZH le★₩vel, like UL CMP level,₩  tests flame retardancy and emitted g₽γ✘ases. As the name suggests, the bu<♣↕rning LSZH does not em™" it halide gases and emits£¥ very low levels of s♣ moke. LSZH grade cables can be used for®≈ copper cables and fiber op®<tic communication cables, ¶×and their structure ↕← is similar to UL grade cables

CM/CMG: General Communication Cablin↕ g. This is common in th¶<e horizontal routing of buildingσλs, where they are typicall☆¶×≥y divided into smaller bundles comp•♥ared to CMR grade cables. When usingπ₽♥ halide based chemicals for CM/C☆÷MG grade cables, the wire assembly •₩may be affected. According to the γ>σdefinition, in a small bun₽✔ dle of cables, CM/CMG cables m ≤Ω✘ust self extinguish wit♠β★₽hin 5 meters of the δ€∞spread of combustion. The flame was ε"↑§not forced to burn by a fan. C→αM/CMG grade cable jackets are☆σ∞♣ usually made of a certain tyβγpe of PVC, which emit>$♣s chlorine in the combus≈‌≥tion chamber. CM/CMG grade≠ε cables are commonly used in h©§★∞orizontal routing in the UK, Asia, • and Australia. CM/CMG grade cabl<✘¥×es must undergo CSA FT-4 "Verti>∏cal Burning Test"

CMX: Residential communicatio÷®±n cabling. This type of cable is l☆©imited to residential or ot≠¶her small applications wheΩ$¥•re the number of com©✔↓®munication cables used §φ♣is very small, and thes✘‌e applications gener↑>ally only lay one cable. CMX ↕£¶πgrade tools cannot be used fo✔∏≈r bundled cable applications. CπΩMX grade cables must undergo UL₽ππ♦ VW1 combustion testing