Agriculture is one of the most dependable markets for used totes. Liquid fertilizer — UAN solutions (urea-ammonium nitrate), starter blends, micronutrient packages — moves through a great many totes every spring in the Midwest. The chemistry is generally tote-friendly, but a few details matter.
UAN-32 chemistry
UAN-32 is roughly 32% nitrogen by weight, a balanced mix of urea, ammonium nitrate, and water. The pH is slightly acidic to neutral (5.8–7.0 typically) and the salt content makes it electrolyte-rich. HDPE handles UAN-32 well. The cage is the more vulnerable part — galvanized steel in contact with UAN drip will corrode at the white-rust stage rapidly.
The practical implication is that cages on UAN-service totes look used. Even with no leaks, the splash and condensation around the bottom valve area accelerates galvanic loss. Inbound UAN totes from a season’s ag service typically have measurably more cage corrosion than non-fertilizer service.
Ammonia odor
UAN totes off-gas trace ammonia continuously as urea slowly hydrolyzes. The odor is faint but persistent and survives a single rinse. If a tote were to go into food service after fertilizer service (it shouldn’t, and here’s why), the ammonia ghost is detectable in lab analysis for many wash cycles.
For continued fertilizer service, the ammonia ghost is irrelevant. The tote can be flushed and refilled with no consequence.
Cold-weather behavior
UAN-32 has a relatively high salt-out temperature — in cold weather the ammonium nitrate component crystallizes, leading to a slushy two-phase mix in the bottom of the tote. The slush is not damaging to the tote but is impossible to dispense through a 2″ valve. For winter storage, either keep the tote above the salt-out temperature on the product’s spec sheet or accept that you need a remelt cycle before spring use.
UAN-28 has a lower salt-out temperature and is more winter-tolerant. Many northern operations prefer 28 over 32 for stored inventory.
Bulk valve choice
Standard EPDM gaskets generally hold up well in UAN service. Galvanized hardware (bolts, valve handles) shows accelerated corrosion. Spec stainless or coated hardware for UAN-dedicated totes if you can.
Tote tagging
UAN-service totes should be permanently tagged as “ag use, ammonia history” before going into any other service. Reputable suppliers won’t move UAN-history bottles into food, brewing, or potable-water applications, regardless of wash status. The market for ag-to-ag turnover is robust enough that the bottles continue in service for many cycles.
Spill containment
Many states regulate bulk liquid fertilizer storage, and secondary containment requirements can kick in above certain volumes. Thresholds and exemptions vary, so check current rules with the Ohio Department of Agriculture (or your state’s agriculture department) before building up inventory. Even where it isn’t required, planning for secondary containment from day one is cheap insurance if you’re stacking several totes.
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