Tests on nine chemicals seized from a trading company's Kowloon Bay storeroom will determine any prosecutions.
If the chemicals are classified as dangerous, the company's bosses could face six months imprisonment and a $25,000 fine for each of a possible nine offences.
The chemicals were stored by the company before being exported to the mainland where, it is understood, they were to be used in the manufacture of imitation jewellery.
Fire officers believe the haul could be up to 100 times the allowed quantity of dangerous and toxic material.
Without a special licence, companies can keep only a set quantity, which varies depending on the particular chemical.
Monday's seizure followed a raid on Fook Hong Industrial Building in Sheung Yuet Road, next door to where two chemical workers were overcome by toxic fumes last Friday.