HSN code 38242090 is the 8-digit tariff item for naphthenic acids, their water-insoluble salts and their esters: other, under heading 3824 and sub-heading 382420 (Chapter 38). GST is 18%: 9% CGST + 9% SGST within a state, or 18% IGST to another state. Rates as of 2026-10-21.
HSN 38242090 at a glance
| Tariff item (8 digits) | 38242090 |
|---|---|
| Heading (4 digits) | 3824: Prepared binders for foundry moulds or cores; chemical products and preparations of the chemical or allied industries (including those consisting of mixtures of natural products), not elsewhere specified or included |
| Sub-heading (6 digits) | 382420 |
| Chapter | 38: Miscellaneous chemical products |
| Description | Naphthenic acids, their water-insoluble salts and their esters: other |
| GST rate | 18% |
| Within the state | 9% CGST + 9% SGST (or UTGST) |
| To another state | 18% IGST |
9/2025-CT(R), Schedule II, S. No. 110 (HSN 3824) covers "Prepared binders for foundry moulds or cores; chemical products and preparations of the chemical or allied industries (including those consisting of..." at 18%. Goods of this code outside that wording fall under the 18% residual entry, so the rate is 18% either way.
The rate entry for this code
The description is the notification's own wording. An entry applies only when the goods match it.
| HSN scope | Description of goods | GST | CGST + SGST | Entry |
|---|---|---|---|---|
| 3824 | Prepared binders for foundry moulds or cores; chemical products and preparations of the chemical or allied industries (including those consisting of mixtures of natural products), not elsewhere specified or included | 18% | 9% + 9% | 9/2025-CT(R), Schedule II, S. No. 110 |
| Any | Goods which are not specified in Schedule I, III, IV, V, VI or VII (residual entry, for goods of 38242090 that match none of the descriptions above) | 18% | 9% + 9% | 9/2025-CT(R), Schedule II, S. No. 639 |
Worked example: a ₹1,000 sale under HSN 38242090
Taxable value ₹1,000.00. Within your state: CGST ₹90.00 + SGST ₹90.00 = ₹180.00, invoice total ₹1,180.00. To a buyer in another state: IGST ₹180.00, the same total.
For other amounts, or to work back from a tax-inclusive price, use the GST calculator.
How many HSN digits to print on the invoice
Notification 78/2020-Central Tax sets the minimum by aggregate turnover in the previous financial year: up to ₹5 crore, at least 4 digits (3824) on tax invoices to registered buyers (optional on B2C invoices); above ₹5 crore, at least 6 digits (382420) on all tax invoices. Exports and imports are declared on the shipping bill or bill of entry under the full 8-digit tariff item (38242090), so most exporters print 8 digits on their GST invoices too.
The HSN-wise summary in GSTR-1 uses the same code, so set it once on the item in your billing software. FundRaksha Book stores the HSN and GST rate on each item, splits CGST, SGST and IGST on every bill, and keeps stock and party ledgers alongside.
Other tariff items under sub-heading 382420
- HSN 38242010: Copper naphthenate (prepared binders for foundry moulds or cores) (18%)
- HSN 38242020: Naphthenic acids (prepared binders for foundry moulds or cores) (18%)
See every rate entry for the heading on the HSN 3824 page, or all Chapter 38 headings.
Sources
Codes and descriptions: GSTN HSN master (HSN_SAC.xlsx, sheet HSN_MSTR), GST portal, file dated 13.10.2026, read on 21.10.2026; descriptions were converted from capitals and joined with their heading and sub-heading text. Rates: Rates from Notification 9/2025-Central Tax (Rate), 17.09.2025, as amended by Notification 19/2025-Central Tax (Rate) (from 01.02.2026) and Notification 01/2026-Central Tax (Rate) (from 01.05.2026); nil-rated goods from Notification 10/2025-Central Tax (Rate); bricks from Notification 14/2025-Central Tax (Rate).