SN/T 4719-2016 in English

Analysis of Standard Technical Framework

Key Operation Points

1. Fumigation Key Controls

Temperature determination utilizes a dual-probe monitoring method: When the warehouse temperature is more than 5°C lower than the internal temperature of the goods, the average value is taken as the baseline temperature. When using a methyl bromide concentration detector, the detection range is required to be 0-120g/m³, and the circulation system must be activated for ≥15 minutes after dosing.

2. Special Requirements for Soaking Treatment

Growing media and lily bulbs must be handled separately. Soaking pools should be ≥50 meters from living areas and fenced. Discarded liquid must be handled under the supervision of environmental protection authorities and in compliance with the management requirements for avermectins in GB/T19337.

Background of Standard Evolution

This standard, based on the SN/T1143 fumigation procedures, establishes specific treatment parameters for lily bulbs for the first time, targeting five key quarantined species (Appendix A), including Braybostomida and Trichodesmida. Technological breakthroughs include:

• A new phosphine treatment solution for the low-temperature range (0-4.9°C)
• A 6-level gradient control system for methyl bromide dosage as it changes with temperature
• An innovative separation and treatment process for bulbs with media

Implementation Recommendations

1. Safety Protection

Operators must be equipped with filter-type gas masks, and the fumigation site should have a methyl bromide poisoning emergency plan as specified in GB7796. A two-person operation mechanism is recommended to ensure timely handling of emergencies.

2. Effectiveness Verification

A final concentration check must be conducted before the end of fumigation. If the test value is lower than the requirements in Appendix B, the CT value (concentration × time) must be recalculated and the difference must be made up. The original concentration record should be attached when issuing the treatment certificate.