The Excel function: CLEAN
Removes all nonprintable characters from text. Use CLEAN on text imported from other applications that contains characters that may not print with your operating system. For example, you can use CLEAN to remove some low-level computer code that is frequently at the beginning and end of data files and cannot be printed.
Important The CLEAN function was designed to remove the first 32 nonprinting characters in the 7-bit ASCII code (values 0 through 31) from text. In the Unicode character set (Unicode: A character encoding standard developed by the Unicode Consortium. By using more than one byte to represent each character, Unicode enables almost all of the written languages in the world to be represented by using a single character set.), there are additional nonprinting characters (values 127, 129, 141, 143, 144, and 157). By itself, the CLEAN function does not remove these additional nonprinting characters. For an example of how to remove these additional nonprinting characters from text, see Remove spaces and nonprinting characters from text.