Catalyzes the hydrolysis of acyl-CoAs into free fatty acids and coenzyme A (CoASH), regulating their respective intracellular levels (PubMed:16934754, PubMed:19170545). Has acyl-CoA thioesterase activity towards medium (C12) and long-chain (C18) fatty acyl-CoA substrates (By similarity) (PubMed:16934754, PubMed:19170545). Can also hydrolyze 3-hydroxyphenylacetyl-CoA and 3,4-dihydroxyphenylacetyl-CoA (in vitro) (By similarity) (PubMed:16934754, PubMed:19170545). May play a role in controlling adaptive thermogenesis (By similarity). a fatty acyl-CoA + H2O = a fatty acid + CoA + H(+) decanoyl-CoA + H2O = CoA + decanoate + H(+) H2O + octanoyl-CoA = CoA + H(+) + octanoate butanoyl-CoA + H2O = butanoate + CoA + H(+) H2O + hexanoyl-CoA = CoA + H(+) + hexanoate H2O + tetradecanoyl-CoA = CoA + H(+) + tetradecanoate H2O + hexadecanoyl-CoA = CoA + H(+) + hexadecanoate dodecanoyl-CoA + H2O = CoA + dodecanoate + H(+) (9Z)-octadecenoyl-CoA + H2O = (9Z)-octadecenoate + CoA + H(+) (5Z,8Z,11Z,14Z)-eicosatetraenoyl-CoA + H2O = (5Z,8Z,11Z,14Z)-eicosatetraenoate + CoA + H(+) kcat is 0.016 sec(-1) for n-decanoyl-CoA hydrolase activity (PubMed:19170545). kcat is 0.0047 sec(-1) for n-octanoyl-CoA hydrolase activity (PubMed:19170545). kcat is 0.022 sec(-1) for n-hexanoyl-CoA hydrolase activity (PubMed:19170545). kcat is 0.047 sec(-1) for n-butyryl-CoA hydrolase activity (PubMed:19170545). kcat is 0.014 sec(-1) for 2-butenoyl-CoA hydrolase activity (PubMed:19170545). kcat is 0.023 sec(-1) for beta-methylcrotonyl-CoA hydrolase activity (PubMed:19170545). kcat is 0.0076 sec(-1) for crotonyl-CoA hydrolase activity (PubMed:19170545). kcat is 0.02 sec(-1) for tiglyl-CoA hydrolase activity (PubMed:19170545). kcat is 0.036 sec(-1) for n-propionyl-CoA hydrolase activity (PubMed:19170545). kcat is 0.054 sec(-1) for acetyl-CoA hydrolase activity (PubMed:19170545). kcat is 0.019 sec(-1) for lauroyl-CoA hydrolase activity (PubMed:19170545). kcat is 0.02 sec(-1) for myristoyl-CoA (at 25 degrees Celsius) hydrolase activity (PubMed:19170545). kcat is 0.07 sec(-1) for myristoyl-CoA (at 37 degrees Celsius) hydrolase activity (PubMed:19170545). kcat is 0.0044 sec(-1) for n-palmitoyl-CoA hydrolase activity (PubMed:19170545). kcat is 0.017 sec(-1) for palmitoleoyl-CoA hydrolase activity (PubMed:19170545). kcat is 0.011 sec(-1) for stearoyl-CoA hydrolase activity (PubMed:19170545). kcat is 0.011 sec(-1) for oleoyl-CoA hydrolase activity (PubMed:19170545). kcat is 0.017 sec(-1) for linoleoyl-CoA hydrolase activity (PubMed:19170545). kcat is 0.022 sec(-1) for arachidonoyl-CoA hydrolase activity (PubMed:19170545). kcat is 1.4 sec(-1) for 3-hydroxyphenylacetyl-CoA hydrolase activity (PubMed:19170545). kcat is 0.19 sec(-1) for 3,4-dihydroxyphenylacetyl-CoA hydrolase activity (PubMed:19170545). kcat is 0.19 sec(-1) for 3,5-dihydroxyphenylacetyl-CoA hydrolase activity (PubMed:19170545). kcat is 0.14 sec(-1) for 4-hydroxyphenylacetyl-CoA hydrolase activity (PubMed:19170545). kcat is 0.084 sec(-1) for phenylacetyl-CoA hydrolase activity (PubMed:19170545). kcat is 0.011 sec(-1) for 3-hydroxybenzoyl-CoA hydrolase activity (PubMed:19170545). kcat is 0.032 sec(-1) for 4-chlorobenzoyl-CoA hydrolase activity (PubMed:19170545). kcat is 0.18 sec(-1) for beta-hydroxybutyryl-CoA hydrolase activity (PubMed:19170545). kcat is 0.05 sec(-1) for glutaryl-CoA hydrolase activity (PubMed:19170545). kcat is 0.079 sec(-1) for 3-hydroxy-3-methylglutaryl-CoA hydrolase activity (PubMed:19170545). kcat is 0.066 sec(-1) for malonyl-CoA hydrolase activity (PubMed:19170545). kcat is 0.083 sec(-1) for methylmalonyl-CoA hydrolase activity (PubMed:19170545). Homotetramer (PubMed:16934754, PubMed:19170545). Interacts with PCTP (By similarity). During interphase, found both in the nucleus and in the cytoplasm. At mitosis, localizes to the spindle. Colocalizes with tubulin. Belongs to the thioesterase PaaI family.