Invisible Gas, Visible Risk — Silent Threat Phosphine

Phosphine is an issue that is invisible during audits but is one of the topics an auditor must know best. More than a gas, it is the transparency and responsibility test of the operator applying it.

Pest control measures are generally checked on site by auditors through the pest control file within hygiene, GMP, HACCP, Food Safety, ISO 22000 and GFSI‑approved standards (FSSC 22000, BRC, IFS, SQF etc.). But is a desk review of only the pest control file sufficient to understand whether requirements have been met? Simple questions you can ask the warehouse manager in the field — “When was the last pest treatment carried out?” and “How is treatment performed when infestation is detected in products?” — can be multiplied. What matters most are the records behind the answer, the precautions taken and who performed the application. If it is claimed that a fumigant was used but no records were kept or shown, can an auditor determine whether pest control practices comply with standards?

Phosphine is powerful, invisible and, when used incorrectly, directly threatens both worker health and consumer confidence.

Regulation and Authorized Use Areas for

Pursuant to the Plant Quarantine Fumigation Regulation, fumigation applications may be carried out only in closed storage environments “in cases of plants, plant products, plant industrial products and forest products; when inspectors determine and deem necessary that they are contaminated with harmful organisms such as insects, mites, nematodes, diseases, weeds as required by the importing country’s phytosanitary quarantine legislation, in import, export, re‑export and transit passages; for cleaning packaging materials, environments where they are located such as warehouses, silos, ship holds, containers and for identifying quarantine pests; for cleaning environments where cultivated plants are grown; and additionally, upon request, in museums, libraries, food producing and storing workshops, factories and completely empty storehouses and warehouses that have been made suitable for fumigation”, and these applications must be performed only by authorized, certified fumigation operators. So what legal basis exists for applications outside the scope of the regulation (e.g., restaurants, hotels, catering that directly serve consumers, consumers’ homes)?

Target Pests and Purpose of Fumigation

Phosphine is particularly effective against stored‑product pests: grain beetles (e.g., Sitophilus spp.), legume pests, tobacco beetles and other pests that proliferate in storage environments. Therefore, its use is envisaged in cases of pest infestations that have contaminated the environment.

Food Contact, Shelf Life and Safety Measures

Food contact: A critical issue in phosphine application is that the gas must not directly contact food. Phosphine kills pests; the active gas must not penetrate into the food. Maximum residue limits (MRLs) for pesticides in foods are determined and controlled by MRL regulations. Phosphine is monitored for these residues, is it not?

Shelf life: Correct and regulation‑compliant fumigation can control pests but does not extend the shelf life of food. Once contamination has occurred, re‑infestation can be observed. Conversely, incorrect application endangers consumer health.

Mandatory precautions: During application, isolation, appropriate PPE and sufficient post‑application ventilation must be provided. The best measures are thorough cleaning of living areas, control of pest harborages, consuming each food within its appropriate shelf life and timely separating contaminated food from other foods.

Measurements, Report and Audit Practice

Regulation requires that, at the end of the fumigation period, whether the environment has been sufficiently ventilated be determined by measurements and recorded. The absence of this field in the official report template does not remove the obligation in the regulation; it only makes documentation and inspections more difficult in practice.

Pest Control Auditor: If the report lacks a measurement field, the auditor must request written evidence from the applicator such as device printouts, the operator’s measurement report or a gas measurement form signed by authorized personnel. If these records cannot be produced, the application is incomplete under the principle “no record means no application.”

Suggested report field (to be added): 

Fumigation Post‑Measurement Results

• Measurement Date/Time: …

• Measurement Location (e.g., warehouse entrance, silo top): …

• Measured Phosphine Concentration (ppm): …

• Comparison with Safety Limit (limit ppm): …

• Responsible Measurer (Name, License No., Signature): …

Phosphine- Pest Control

Auditor’s Role

The auditor gives the business this clear message: “No record means no application. No precaution means increased risk. If an unauthorized person performed the application, this is both a legal and ethical violation.” Phosphine is not merely a technical matter in inspections; it is a mirror of the company’s safety culture. Would adding a measurement results section to the report format strengthen regulatory compliance and eliminate ambiguities in inspections?

Useful Information (Source: Plant Quarantine Fumigation Regulation)

What is a fumigant? Substances used in fumigation that act in gaseous form on harmful organisms; they may be solid, liquid or gaseous pesticides. 

What is fumigation? The process of introducing a fumigant that acts in gaseous form into a closed environment at a specified temperature in a specified amount and holding it there for a specified period to destroy harmful organisms. 

What is a fumigation area? The area adjacent to the place where fumigation is carried out where approaching poses a life‑threatening danger. 

What is a fumigation report? The document prepared and signed by the authorized representatives of those requesting fumigation and the fumigation operators.

Sources: Plant Quarantine Fumigation Regulation — https://www.mevzuat.gov.tr/mevzuat?MevzuatNo=15057&MevzuatTur=7&MevzuatTertip=5

26.11.2025 Fatma (Akkuş) İnceoğlu