Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE table_name_90 ( chemical_class VARCHAR, example VARCHAR )

### Question ###
Which chemical class uses the example Chloroethane (ethyl chloride)?

### Accurate SQL ###

SELECT chemical_class FROM table_name_90 WHERE example = "chloroethane (ethyl chloride)"