Fumigants and hazardous preservatives

Employees must be removed from a space when the concentration reaches the level specified as hazardous by the fumigant manufacturer or the level in Table Z-1 of [29 CFR 1910.1000], whichever is lower. See 1917.25(a) and the Table Z-1 exposure limits in 1910.1000.

• Check the fumigant manufacturer's label and Safety Data Sheet (SDS) for the manufacturer's hazardous concentrations and compare to the applicable value in Table Z-1.
• Do not allow re-entry until tests demonstrate the atmosphere is safe as required by 1917.25(a).
• For recordkeeping and monitoring details, follow the testing and record rules in 1917.25(b)–(c).

Tests must be appropriate for the hazard, conducted by designated persons, and performed at intervals necessary to ensure exposures stay below the permissible exposure limit. See 1917.25(b)(1)–(3).

• Appropriate for the hazard means selecting test methods and instruments that can detect the fumigant or preservative at the action level or PEL (for example, gas detectors, colorimetric tubes, or laboratory analysis) and are sensitive to the concentrations of concern.
• Designated persons should be trained and competent to operate instruments, collect samples, and interpret results as required by 1917.25(b)(2).
• Establish monitoring frequency based on the chemical’s properties, cargo type, ventilation, and past readings so exposures remain below limits per 1917.25(b)(3).

Test results must be retained and available for at least 30 days and may be recorded on any retrievable medium. See 1917.25(c).

• Records must be retrievable and kept in a way that they can be inspected (paper files, electronic records, or database entries are acceptable).
• Ensure records include date/time, location, chemical monitored, instrument or method used, personnel who performed the test, and results so they are meaningful for inspections and internal review.

Only designated persons are permitted to apply these chemicals to cargo. See 1917.25(d).

• "Designated persons" should be identified by the employer, trained in safe handling and application, and competent in the use of the chemicals and equipment.
• Employers should document designation and training to demonstrate compliance with 1917.25(d).

Persons entering a hazardous atmosphere must be protected by respiratory and emergency protective equipment that meets the requirements of [Subpart E of Part 1917]. See 1917.25(e)(1) and 1917 Subpart E.

• Subpart E lists required types of respirators, protective clothing, emergency escape equipment, and maintenance/use procedures—use those rules to select equipment.
• Equipment must be inspected, maintained, and workers must be trained in its use; confirm compatibility of respirator type with the specific fumigant or preservative before entry.

Designated persons entering a hazardous atmosphere must be instructed in the nature of the hazard, precautions to take, and the use of protective and emergency equipment, and standby observers—equipped and instructed—must continuously monitor their activity. See 1917.25(e)(2).

• Training must cover the chemical hazard, symptoms of exposure, correct PPE use, emergency procedures, and communication methods.
• Standby observers must be positioned to continuously monitor entrants, be ready to initiate rescue or emergency procedures, and wear the same protective equipment and training.

Signs must clearly note the danger, identify the specific chemical hazards, and give appropriate information and precautions including instructions for emergency treatment of affected employees. See 1917.25(f).

• Include the name of the chemical(s), hazard warnings (for example, "Fumigant—Do Not Enter"), required PPE, entry restrictions, and emergency first-aid measures.
• Make signage clear, visible at likely points of entry, and update signs if conditions or chemicals change.

Containerized shipments of fumigated tobacco must be aerated for 48 hours after fumigation and prior to loading; when tobacco is in shipping cases with polyethylene or similar bag liners, the aeration period must be 72 hours. See 1917.25(g).

• Employers must obtain a written warranty from the fumigation facility confirming the appropriate aeration period has been met before loading or transporting the container.

The employer (the party loading or transporting the fumigated tobacco) must obtain a written warranty from the fumigation facility stating that the appropriate aeration period has been met. See 1917.25(g).

• The warranty should identify the container, date/time fumigation completed, the aeration period applied (48 or 72 hours as required), and a statement that aeration was completed before loading.
• Keep the warranty with cargo shipping records and make it available for inspection if requested.

Employers must use whichever concentration is lower—the level specified by the fumigant manufacturer or the value in [Table Z-1 of 1910.1000]. See 1917.25(a) and the Table Z-1 exposure limits in 1910.1000.

• Review the manufacturer’s label and SDS for the chemical’s recommended hazardous or action level.
• Compare that value to the relevant PEL or exposure limit in Table Z-1 and use the more protective (lower) number to determine when employees must be removed.

An employer should set monitoring intervals based on the chemical hazard, cargo characteristics, ventilation, past monitoring results, and the work tasks so that employee exposure does not exceed the permissible exposure limit. See 1917.25(b)(3).

• Factors to consider: volatility of the chemical, containerization (sealed or leaking), weather/temperature, cargo off-gassing rate, and work duration.
• Document a monitoring plan specifying methods, instruments, and frequency; adjust intervals if conditions change or monitoring shows rising levels.

A "designated person" must be appointed by the employer and be trained and competent to perform atmospheric testing appropriate for the hazard. See 1917.25(b)(2).

• Competence generally includes training on test methods and instruments, understanding exposure limits (e.g., Table Z-1), and the ability to interpret results and take protective action.
• Employers should document designation, training records, and instrument calibration/maintenance to show compliance.

No—only designated persons may enter hazardous atmospheres; non-designated employees must not enter even if provided PPE unless they have been designated and trained. See 1917.25(e).

• If an unplanned need arises to enter, the employer must designate, train, and equip the individual before entry and ensure standby observer coverage as required by 1917.25(e)(2).

Test records must be available for inspection for at least 30 days and may be produced in any retrievable medium when requested by inspectors or authorized parties. See 1917.25(c).

• Make records accessible (paper or electronic) and provide copies to OSHA, employees, or their representatives upon request in accordance with inspection procedures.

OSHA requires signs that clearly note the danger and identify specific chemical hazards, but it does not prescribe specific languages; employers should use the languages necessary to communicate hazards effectively to their workforce. See 1917.25(f).

• If your workforce has non-English speakers, include additional languages or pictograms so the message is understood by affected employees.
• Ensure signs include required emergency treatment instructions and are placed where they will be seen by anyone approaching the hazard area.

When tobacco is within shipping cases that have polyethylene or similar bag liners, the aeration period must be 72 hours after fumigation before loading. See 1917.25(g).

• Containers without such liners require 48 hours of aeration; document the liner status and aeration time on the written warranty from the fumigation facility.

Yes—respiratory protection used for entry into hazardous atmospheres must meet the requirements in [Subpart E of Part 1917], which include proper selection, fit, inspection, maintenance, and training. See 1917.25(e)(1) and 1917 Subpart E.

• Follow Subpart E procedures for respirator selection, medical evaluation, fit checking, cleaning, and storage.
• Keep records of respirator maintenance and training per Subpart E requirements.

Handheld electronic gas detectors are acceptable if they are appropriate for the specific fumigant hazard, calibrated, and operated by designated persons trained to interpret results. See 1917.25(b)(1)–(2).

• "Appropriate" means the detector must be sensitive to the compound at the action level/PEL and be reliable for the chemical matrix (humidity, temperature, interferents).
• Maintain calibration logs and follow instrument manufacturer procedures; document use as part of the records required by 1917.25(c).

If the fumigant manufacturer does not specify a hazardous concentration, use the exposure limits in [Table Z-1 of 1910.1000] to determine when employees must be removed. See 1917.25(a) and 1910.1000 Table Z-1.

• Use the lower value if the manufacturer provides a number; otherwise apply the Table Z-1 PEL relevant to the chemical.
• When in doubt, err on the side of protection and treat the atmosphere as hazardous until testing shows safe levels.

The standby observer must be continuously monitoring the entrants, be equipped and instructed in emergency procedures, and be prepared to initiate rescue or summon emergency help. See 1917.25(e)(2).

• Duties include maintaining visual or voice contact, watching for signs of exposure or distress, maintaining communication, and triggering emergency response if needed.
• The standby observer must wear the same protective and emergency equipment as entrants and be trained in its use before assignment.