Toxic and Concerned Chemical Substances Transportation Management Regulations Article 14

An error within ± 5% of the total amount is allowed for the declaration of toxic chemical substances transported in bulk. However, the actual transportation amount must be declared to the municipality or county (city) competent authority within three working days, after the shipment is completed.
中文原文 毒性及關注化學物質運送管理辦法第14條
散裝運送之申報,其數量容許上下各百分之五以內誤差。
但應自事實發生之翌日起三個工作日內,向起運地之直轄市、縣(市)主管機關申報實際運送數量。

English translation for reference only; the Chinese text prevails. Not legal advice.