Its research showed that the US consumes 40 per cent of Thai shrimp export and 20 per cent of tuna export.
The US reserves the rights to impose sanctions within 90 days after the downgrade was announced.
SCB also noted that the downgrade will send a negative psychological impact to the global community. Trade competitors may use this as a reason to steal buyers from Thailand.
It added that this downgrade also tarnishes Thailand's image in the international community. Some multinational companies may revise investment schemes.