California waste code 431 Sludge built on phosphate, often from plating or fertiliser plants.

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Sludges
Phosphate sludge

Phosphate characterizes the hazardous sludge.

Hazardous sludge characterized by phosphate, often from plating or fertilizer plants. Alum, gypsum and lime sludge differ.

Is California code 431 hazardous waste?

Not from the code alone. Waste must first be found hazardous. Code 431 isn't a restricted code, but a restricted category that fits takes priority over it. A code that isn't restricted doesn't make waste non-hazardous.

When a shipment needs the Uniform Hazardous Waste Manifest, enter 431 in Item 13 for the waste line. Use one California code, plus the federal RCRA codes when the waste is federally hazardous.

RCRA waste meets a federal listing or characteristic, with no federal exclusion that applies. Non-RCRA waste is hazardous under California rules only. California presumes hazardous waste is RCRA unless the generator shows it isn't, so keep that determination.

What does California code 431 cover?

This code is for hazardous sludge marked by phosphate. The process must use a phosphate input or analysis must find phosphate. The sludge's look alone doesn't settle the code.

Official wording: 22 CCR division 4.5, chapter 11, Appendix XII(b)

Is phosphate sludge California code 431, 411 or 421?

Code	When it fits
431	Process inputs or analysis resolve phosphate as the material characterizing the sludge.
411	Process inputs or analysis resolve the sludge as alum or gypsum rather than another named material.
421	Process inputs or analysis resolve lime as the material characterizing the sludge.

Keep the input or analysis evidence. If more than one named material fits, the regulations don't say which code wins.

Which wastes take California code 431?

Waste	When it’s 431
Phosphate sludge	Process inputs or analysis identify phosphate in the settled residue

Which codes sit beside California code 431?

Code	What it is
441	Sulfur sludge
451	Sludge from degreasing
461	Paint sludge
471	Paper-processing sludge or pulp
481	Tetraethyl-lead sludge
491	Other hazardous sludge