U.S. exports of Polystyrene (Non-Expandable) in Primary Forms, NESOI (HS 390319) totaled $21.1M in August 2026.
Importers of Polystyrene (Non-Expandable) in Primary Forms, NESOI paid $552K in duties in August 2026, an average duty rate of 8.32% — duty actually collected as a share of the imports that cleared customs, not the published tariff schedule. Polystyrene (Non-Expandable) in Primary Forms, NESOI imports of $6.6M in August 2026 ran 24% above the year-to-date monthly average of $5.3M.
Last updated: August 2026 dataNon-expandable polystyrene in primary forms — general-purpose (GPPS) and high-impact (HIPS) grades — is a foundational resin for injection-molded consumer goods, disposable foodservice items, electronics housings, and medical device components. The entire heading resolves to a single 10-digit line (3903190000), so the principal classification issue is distinguishing non-expandable grades from EPS (heading 390311) and from acrylonitrile-butadiene-styrene (ABS) copolymers classified elsewhere. Mexico and Taiwan lead US imports under this heading, with Canada and Japan also significant. Importers sourcing from China should note that Chinese-origin polystyrene may be subject to Section 301 tariffs.
AI-written summary of the official U.S. Census Bureau trade figures on this page — verify before relying on it.
219 import shipments a month
HIPS is a rubber-toughened polystyrene in which polybutadiene is dispersed as a separate phase within a polystyrene matrix — it is still classified as a polystyrene under heading 390319. ABS, by contrast, is a true terpolymer of acrylonitrile, butadiene, and styrene and is classified under heading 3903 as an acrylonitrile-butadiene-styrene copolymer. The distinction affects both the applicable duty rate and any trade-remedy exposure, so importers should obtain a polymer composition certificate confirming the resin type.
A manufacturer's certificate of analysis confirming the absence of an incorporated blowing agent, along with the resin's bulk density and bead or pellet morphology, is the most effective supporting document. CBP may also accept a technical data sheet from the resin producer. Importers should retain these records for at least five years in case of a post-entry audit.
Subheading 3 of 5 in heading 3903
Subheading 390319 · $21.1M of $108.0M
Trade Directory
List your company under HS 390319 — Polystyrene (Non-Expandable) in Primary Forms, NESOI, so the companies trading it can find you. Be the first supplier listed.
HS10 import codes under this HS6 parent, each with its own page. Source: U.S. Harmonized Tariff Schedule.
| Code | Description | Imports for consumption | Average duty rate | Dutiable Share | Duty Collected |
|---|---|---|---|---|---|
| 3903190000 | Polystyrene, NESOI | $6.6M | 8.32% | 45.53% | $552K |
HS10 export codes under this HS6 parent, each with its own page. Source: U.S. Schedule B export classification.
| Code | Description | Export Value |
|---|---|---|
| 3903190000 | Polystyrene, NESOI | $21.1M |
Import lines come from the U.S. Harmonized Tariff Schedule and export lines from Schedule B. The two are numbered by different agencies, so the same 10-digit code can appear in both tables describing a different product.
ImportsExports
Imports
$6.6MYoY · free account
Exports
$21.1MYoY · free account
12-mo low · imports
Low · free accountOver the twelve months to August 2026, the U.S. imported $58.0M of Polystyrene (Non-Expandable) in Primary Forms, NESOI and exported $227.1M.
Through August 2026. Source: U.S. Census Bureau.
Exports · August 2026
destination
Mexico and Canada together take 79% of it.
customs district
origin
entry
rate provision · imports
54.5% enters free of duty; duty collected equals 8.32% of imports for consumption.