# Herbicides: Production route How phosphorus and glycine become the world's top weedkiller Source page: https://www.materialinsights.org/chemicals/herbicides/routes/ How phosphorus and glycine become the world's top weedkiller What this tab covers How it is made: the main production routes or, for product families, the main product types and technologies, compared on share of supply, inputs per tonne, plant scale, yield, co-products and unit cost. Herbicides are a family of hundreds of active ingredients. A few dominate tonnage: glyphosate, glufosinate, the auxins 2,4-D and dicamba, the triazine atrazine, chloroacetanilides such as acetochlor and S-metolachlor, paraquat, and newer HPPD and PPO inhibitors. Most are off-patent, so cost of the intermediates decides who wins. China makes most generic technicals; India is the second hub; Bayer, Syngenta, BASF and Corteva keep integrated plants for key molecules and new modes of action. #### Routes compared | Route | Share of supply | Inputs per tonne | Typical scale | Yield | Co-products | Unit cost | |---|---|---|---|---|---|---| | **Glyphosate: glycine route (main Chinese route)** | most of China's roughly 700 kt/yr glyphosate capacity (indicative) | stoichiometric minimum about 0.44 t glycine, 0.18 t formaldehyde, 0.65 t dimethyl phosphite and 0.18 t phosphorus per t glyphosate acid; actual use is higher (indicative) | 30-200 kt/yr per producer (indicative) | about 80-85% on phosphorus (indicative) | methyl chloride (recovered), salty mother liquor with residual glyphosate, needing treatment | cash cost often RMB 20,000-25,000/t when yellow phosphorus and glycine are cheap (indicative) | | **Glyphosate: IDA route (Bayer and some Chinese producers)** | Bayer capacity over 370 kt/yr (China Agrochemical Insights, 2022) | about 0.8 t IDA equivalent and 0.18 t phosphorus per t glyphosate (stoichiometric, indicative) | Bayer's integrated US chain is the largest single system (indicative) | high on IDA (indicative) | formaldehyde and CO2 from oxidation; less salt than glycine route | not published | | **Glufosinate-ammonium** | global technical capacity 154,970 t/yr in 2025, up from 52,095 t/yr in 2021 (CCM 2025) | not published | 5-30 kt/yr per plant (indicative) | not published | salts and phosphorus waste | price near cash cost at about $6,500/t in 2025 (CCM) | | **Auxins, triazines and chloroacetanilides (2,4-D, dicamba, atrazine, acetochlor, S-metolachlor)** | together probably 20-30% of herbicide tonnage (indicative) | atrazine needs about 0.85 t cyanuric chloride and about 0.5 t of amines per t (stoichiometric, indicative) | 10-100 kt/yr (indicative) | high (indicative) | HCl and salts; chlorophenol traces in 2,4-D | not published | | **Newer patented and selective herbicides (HPPD, PPO, ALS inhibitors, pre-emergents)** | small tonnage, large share of value (indicative) | many steps; fluorinated building blocks | 1-10 kt/yr | not published | solvent and salt waste, high E-factor | not published | #### How each route works **Glyphosate: glycine route (main Chinese route)** Glycine, paraformaldehyde and dimethyl phosphite react in methanol with triethylamine, then hydrolysis with hydrochloric acid gives glyphosate acid. Dimethyl phosphite comes from phosphorus trichloride and methanol, and phosphorus trichloride from yellow phosphorus and chlorine. Lowest cost in China; heavy wastewater and dependent on power-hungry yellow phosphorus. stoichiometry; indicative industry estimates **Glyphosate: IDA route (Bayer and some Chinese producers)** Iminodiacetic acid, made from diethanolamine (Bayer) or from hydrogen cyanide and formaldehyde, reacts with phosphorous acid and formaldehyde to PMIDA, which is oxidised to glyphosate. Bayer runs this at Luling, Louisiana, with phosphorus from Soda Springs, Idaho. Cleaner and integrated; depends on cyanide or diethanolamine chains. China Agrochemical Insights (Jul 2022); indicative **Glufosinate-ammonium** Multistep phosphorus chemistry (methyl phosphonous dichloride or diethyl methylphosphonite with acrolein and cyanide, then hydrolysis). Newer L-glufosinate uses enzymatic or chiral routes to make only the active isomer at half the dose. Works on glyphosate-resistant weeds; overbuilt in China. CCM (cnchemicals, 2025) **Auxins, triazines and chloroacetanilides (2,4-D, dicamba, atrazine, acetochlor, S-metolachlor)** 2,4-D is made from phenol, chlorine and chloroacetic acid; atrazine from cyanuric chloride (from HCN and chlorine) with ethylamine and isopropylamine; acetochlor and metolachlor from substituted anilines and chloroacetyl chloride. Cheap and broad; atrazine is banned in the EU and drift from dicamba led to US court rulings. stoichiometry; indicative **Newer patented and selective herbicides (HPPD, PPO, ALS inhibitors, pre-emergents)** Mesotrione, topramezone, saflufenacil, pyroxasulfone, tetflupyrolimet and others are multistep fine chemistry, often fluorinated, made under patent by the innovators or by Indian and Chinese custom manufacturers. New modes of action for resistant weeds; long and costly registration. indicative; PI Industries, whose custom synthesis exports were Rs 5,412 crore in FY2026 (company, May 2026), supplies such molecules Unit economics are indicative ranges from the sources named; costs move with feedstock and energy prices, plant size and region. ## Other sections - [Summary](https://www.materialinsights.org/chemicals/herbicides/index.md) - [Overview](https://www.materialinsights.org/chemicals/herbicides/overview/index.md) - [Correlation](https://www.materialinsights.org/chemicals/herbicides/correlation/index.md) - [Production](https://www.materialinsights.org/chemicals/herbicides/production/index.md) - [Feedstocks](https://www.materialinsights.org/chemicals/herbicides/feedstocks/index.md) - [Cycles](https://www.materialinsights.org/chemicals/herbicides/cycles/index.md) - [Trading](https://www.materialinsights.org/chemicals/herbicides/trading/index.md) - [Movement](https://www.materialinsights.org/chemicals/herbicides/movement/index.md) - [Regulation](https://www.materialinsights.org/chemicals/herbicides/regulation/index.md) - [Characteristics](https://www.materialinsights.org/chemicals/herbicides/characteristics/index.md) - [Emissions](https://www.materialinsights.org/chemicals/herbicides/emissions/index.md) - [Relationships](https://www.materialinsights.org/chemicals/herbicides/links/index.md)