The dangerous package certificate has an expiry date, within the validity period can always be used, but there is another point is that the dangerous package certificate and the number of pieces of inspection, each time after the use of this number of pieces will be written off, only until the expiry date of the write-off, it can not be used. The expiry date on the Dangerous Goods Certificate is in fact based on the expiry date of the packaging performance sheet. Dangerous goods require dangerous goods packaging. All dangerous goods packaging will have an expiry date. It is usually within one year