Texas Form Code · Inorganic Liquids
Spent caustic
Waste Form
Inorganic Liquids
Form Code
109
Regulation
30 TAC §335.521(c)
Under 30 TAC §335.503 every Texas industrial waste stream is coded with an 8-digit waste code: a 4-character sequence number assigned by the generator, this 3-digit form code, and a 1-character classification.
HHazardous Waste
Waste that is listed or characteristic hazardous waste under the federal RCRA rules (40 CFR Part 261), as adopted by reference in Texas. Carries EPA waste codes (D, F, K, P, U) alongside the Texas code.
1Class 1 Industrial Waste
Nonhazardous industrial waste that is potentially threatening: Class 1 toxic constituents at or above maximum leachable concentrations, ignitable (liquid flash point below 150 F or readily ignitable solid), corrosive (pH 2 or below, or 12.5 or above), 20 ppm or more total recoverable cyanides, or lacking the data to prove a lower class.
2Class 2 Industrial Waste
The default nonhazardous class: any industrial solid waste that does not meet the definition of hazardous, Class 1, or Class 3. Most routine industrial waste streams classify as Class 2.
3Class 3 Industrial Waste
Inert and essentially insoluble industrial waste posing no threat to human health or the environment: rock, brick, glass, dirt and certain plastics and rubber. Requires leachate testing showing no exceedances and no detectable TPH or PCBs.
A waste stream carrying form code 109 can classify as any of the four, depending on its constituents. Classification H streams also carry federal RCRA waste codes.
Aqueous and acid/caustic waste streams: spent acids and caustics, cyanide-bearing solutions, scrubber water, leachate and brines. Metal and cyanide content drives both the form code and the classification.
Recognized recovery routes for this waste family, ranked by typical recovery tier. Which route fits depends on your specific stream — composition, volume and region.
Spent acids and caustics are regeneration candidates: spent pickling and etching liquors can be processed for acid recovery or metal-salt by-products, depending on free-acid strength and dissolved metal load.
40 CFR 261.1(c)(4) — reclamationMetal-bearing streams route to high temperature metals recovery or hydrometallurgical processing, where the contained metals are extracted and returned to commerce as secondary raw material.
40 CFR 268.42 Table 1 — HTMR technology standardStreams hazardous only for corrosivity can be treated in an elementary neutralization unit — a recognized unit type that manages the characteristic without a full treatment permit.
40 CFR 260.10 — definitionsThese are the typical routes for inorganic liquids. Your stream's actual options depend on its composition and where it sits.
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