Cotton Lint Quality & Buyer Specification Guide

Grading systems -- HVI measurement, and more than one national reference grade

Modern cotton classing combines human classer judgment (color grade, leaf grade, extraneous matter) with instrument measurement on a High Volume Instrument (HVI), which outputs a standard set of fiber properties used worldwide. There is no single global regulator of the grading scale itself -- the United States (USDA Agricultural Marketing Service), Australia and other producing countries each publish their own base/reference grade and premium-discount schedule built on the same underlying HVI measurements:

Sources: North Carolina State Extension, Cotton Information; USDA AMS, Cotton Classification: Understanding the Data; Cotton Incorporated, Cotton Fiber Quality.

Micronaire, staple length and leaf grade -- the US reference numbers

USDA's own premium/discount schedule (via the Farm Service Agency's loan program, which both sets a market-relevant reference point and is one of the few places these numbers are published with real figures attached) uses a base grade of color grade 41, staple length 34 (32nds of an inch, i.e. 1-1/16"), and leaf grade 4. For micronaire, the commonly cited no-discount band is 3.5-4.9, with one trade source narrowing the actual premium band to 3.7-4.2 and another describing premiums continuing up to 4.9 -- we report both rather than pick one, since they may reflect different crop years' price schedules rather than a fixed rule. Discounts apply below 3.5 and above 5.0.

Leaf grade runs 1 (cleanest) to 7, each tied to a physical reference standard rather than a bare percentage. One research estimate puts average trash content at roughly 1%, 2%, 3% and 4% by mass for leaf grades 1 through 4 respectively, but the same source cautions that actual trash content for any individual sample can vary by as much as ±100% of that average -- treat these as indicative, not a guaranteed lab-equivalent figure.

A genuine national difference, not a transcription error: Australia's own classification base grade is reported elsewhere as color 31 (Middling), leaf 3, staple 36 (32nds) and micronaire G5 (3.5-4.9), with a base strength of 28 g/tex -- a different reference point on every axis (color, leaf, staple) from the US base grade above, even though both systems measure the same underlying HVI properties. We could not independently confirm an equivalent single US base-grade strength figure (only that higher g/tex earns a premium and lower earns a discount), so the 26.0-28.9 g/tex range we found cited is reported here as the Australian figure, not confirmed as a US-equivalent number. Sources: Ag Economics on the Plains (Texas A&M AgriLife), "Understanding the Relationship Between Cotton Classing and Cotton Prices"; USDA FSA, 2026 Cotton Loan Schedule; Cotton Incorporated classification pages; a secondary trade explainer citing Australian base-grade figures (reported as such, not independently verified against CICCA's own primary text).

Uniformity index: roughly 80-82% is described as the US average/"intermediate" range; below 78% is considered poor uniformity, 83% and above is considered good, and above 85% is considered very high uniformity.

Moisture

Sources describe moisture in two different contexts that are easy to conflate -- processing-optimum guidance for mills versus a fixed packaging specification for gin bales:

We did not find a Tanzania- or TCB-published moisture specification distinct from these international figures -- treat the ranges above as general industry reference points, not a confirmed Tanzania-specific requirement. Sources: CRDC Project CTFT20, Final Report, Moisture in Cotton Ginning Review; 2021 Specifications for Cotton Bale Packaging Materials (Joint Cotton Industry Bale Packaging Committee).

Packaging and bale weight

The one figure we could independently confirm is the US "universal density" (UD) gin bale: net weight 500 lb (226.8 kg), dimensions roughly 1.37-1.40m × 0.51-0.53m with average bulge thickness 0.84m, and a density of 28 lb/ft³ (472 kg/m³) -- close to, but not identical to, the ISO 8115 international standard figure of 450 kg/m³ cited elsewhere. Bagging material for a UD bale must weigh at least 7.7 oz/yd² and at least 3 lb per bag at 8.5% moisture.

We could not confirm a Tanzania- or East-Africa-specific lint bale weight. The brief figure of roughly 170-227kg commonly quoted for African origins could not be traced to a specific primary source during this research pass -- rather than present an invented "typical African bale weight," we are flagging this as unverified. Buyers sourcing from Tanzania should confirm bale weight directly with the ginnery or exporter rather than assume the US 226.8kg figure applies.

Sources: cotton.org (National Cotton Council / Joint Cotton Industry Bale Packaging Committee), U.S. Cotton Bale Dimensions; ISO 8115:1986, Cotton bales -- Dimensions and density (title/summary; primary standard text not independently read).

Tanzania-specific: what the Cotton Board actually regulates

The Tanzania Cotton Board (TCB), headquartered in Mwanza and operating under the Cotton Industry Act (Cap. 201) and its Regulations, runs the licensing side of the sector: cotton buying licenses (entitling the holder to buy seed cotton from growers), lint export licenses (requiring a valid seed-cotton buying license plus a TCB-issued lint quality certificate), and distribution oversight for agro-inputs -- in the 2023/2024 season the Ministry of Agriculture distributed 24,318 tonnes of cotton seed through TCB channels, 110% of a 22,146-tonne target.

On grading specifically, Tanzania's Cotton Regulations require every grower to grade seed cotton into Grade A or Grade B before sale, and give the Board power to specify which grade may be bought or sold in a given area during a given period. We could not find the numeric criteria distinguishing Grade A from Grade B (e.g. trash content, moisture, color thresholds) -- the regulations document that should define this was not legible in the copy we accessed, so we are flagging this as an open gap rather than guessing at the cutoff. Separately, lint intended for export requires its own TCB lint quality certificate, which trade-advisory sources describe as based on staple length, micronaire, strength and contamination level -- consistent with the HVI properties above, but again without a published Tanzania-specific numeric table we could independently verify.

Ginning outturn (lint recovered as a percentage of seed-cotton weight) is a live economic issue for the sector: the long-dominant UK91 variety returns roughly 34% lint, 62% seed; across 1990-2010 the national ginning-outturn ratio is reported to have ranged 28%-35%; a newer variety, UKM08, is reported at 42% lint, 54% seed with a 25% higher yield -- a real improvement if adopted at scale, though we did not find data confirming what share of national production now uses UKM08 versus UK91. For comparison, other Southern African producers are reported to average ginning outturns above 40%, which the same sources frame as a competitiveness gap for Tanzania.

Production is concentrated in the Western Cotton Growing Area -- Shinyanga, Simiyu, Mwanza, Mara, Geita, Tabora, Kigoma and Singida -- which together account for an estimated 97-99% of national production. Within that area, Simiyu alone is reported at roughly 47% of national output, with Mwanza around 10%, and Tabora and Geita around 9% each; Shinyanga and Mwanza are also separately described as the two largest cotton-growing regions, a framing that doesn't perfectly reconcile with the Simiyu-led percentage breakdown -- we report both rather than resolve the discrepancy ourselves.

Tanzania's cotton export levy is not something we could pin to a single cotton-specific published figure the way cashew's CBT levy is documented. The general produce cess applicable to cash crops in Tanzania is capped at 3%, per Tanzania Revenue Authority guidance, but we did not find a TCB document setting a cotton-specific levy rate the way the Cashewnut Board publishes its USD160/MT-or-15%-FOB formula -- treat the 3% cess as general tax-law context, not a confirmed cotton-specific export levy.

A separate, pilot-stage development: the Tanzania Mercantile Exchange (TMX), operating since 2018, has cotton listed among the crops being piloted for exchange-based trading, alongside sesame and other agricultural commodities already trading on the platform -- we found no confirmation that cotton auctions on TMX are yet in full, ongoing operation (as cashew's RCN auctions are), so we describe this as a pilot rather than a live trading channel.

Sources: Tanzania Cotton Board; Cotton Industry Regulations, 2011 (partially legible in the copy reviewed); FAOLEX, Cotton Industry Act (Act No. 2 of 2001); allAfrica, "Poor Seeds Hold Back Tanzania's Cotton"; UNCTAD, Analysis of cotton by-products survey in Tanzania; ICAC, Tanzania Cotton Production and Productivity; Wikipedia, Shinyanga Region / Simiyu Region (secondary aggregation of regional production shares); Tanzania Mercantile Exchange.

Tanzania Cotton Board official logo -- (Official organization brand asset — used for directory identification)

Export documentation & HS codes

Raw cotton (neither carded nor combed) falls under HS 5201; carded or combed cotton falls under HS 5203 -- Tanzanian lint exports, being baled raw ginned lint rather than further-processed carded/combed fiber, would typically fall under 5201 unless sold in a carded/combed form. Documentation commonly required for Tanzanian cotton lint exports includes a TCB export permit and lint quality certificate, a phytosanitary certificate from the Ministry of Agriculture's Plant Health Services (reported processing time 1-2 working days, reported fee around USD 15 plus weight-based inspection fees), a plant export permit/stamp, Commercial Invoice, Packing List, Bill of Lading and Certificate of Origin. We assembled this from several converging trade-advisory sources rather than one single consolidated government manual -- see our wider Quality Inspection & Pre-Shipment Verification and Incoterms for Commodity Buyers guides for the cross-commodity detail behind both.

Sources: Tanzania Trade Portal, Phytosanitary certificate approval procedure; afriexports.com, Export Documentation in Tanzania; zatra.co, Exporting from Tanzania: Permits and Documents.

Harvest timing -- a real but not perfectly consistent picture

Sources converge on a planting window of mid-November to mid-December (tied to the Western Cotton Growing Area's unimodal rainfall pattern), with harvest beginning roughly six months later. Where sources differ slightly is the exact harvest span: one account describes harvesting as beginning in May and running through June, with the buying season opening in May; another describes the main harvest as June-July, ending in August, with early-sown cotton ripening and picked from late May. We treat May as the earliest start reported and August as the latest reported end, rather than asserting one single narrow window -- see the harvest calendar above for how we've encoded this.

Sources: Daily News, "Tanzania eyes cotton output recovery to 300,000 tonnes"; PMC, "Impact of sowing date and level of phosphorus application on economic returns in cotton"; Frontiers in Plant Science, sowing-date/phosphorus study (Chato District); Selina Wamucii, "Tanzania Cotton."

Buyer specification checklist

Sample & inspection guidance

• Appearance -- color consistency (white/creamy, not gray or yellowed), visible trash/leaf content, fiber length consistency by eye and touch.
• Handle -- fiber should feel soft and relatively uniform; excessive harshness or obvious short-fiber content is a visible, if imprecise, defect signal.
• Contamination -- visible plastic, bark, or foreign matter in a sample is a red flag regardless of what the quoted leaf/trash grade says.
• Bale condition -- intact bagging/strapping, no moisture staining or mold odor.

A visual/handle sample check is a screening step, not a substitute for laboratory testing. Micronaire, staple length, strength, color grade and uniformity index all require HVI equipment to confirm -- not inspection by eye. Our general Quality Inspection & Pre-Shipment Verification guide covers the wider pre-shipment inspection process that applies across commodities, including cotton.