Controls whether the internal memory allocation and deallocation routines used by OEChem (and other OpenEye toolkits) should use slower thread-safe implementations, or faster single-threaded versions. By default, this value is true. This allows OEChem molecules and other toolkit objects to be allocated and deallocated simultaneously in concurrent operating system threads. However, for applications that only have a single thread of execution, the use of thread-safe mutual exclusion can cause a small performance overhead on some platforms. The current setting can be inspected by calling the OEGetThreadSafe function.