Displaying only Characters and Number in SQL

Sometimes there might be special characters and extended ASCII Characters in the Data and it needs to be removed. Usually presence of extended ASCII Characters can result in Report Output. Below is the simple query to restrict it.

select regexp_replace(description,'[^0-9a-zA-Z]','') str, description from mtl_system_items where segment1 =p_item_code;

set define off;
select regexp_replace('The Social & Sport Contribution Fund','[^0-9a-zA-Z ]','') str from dual;