# Yantai Dasteck Chemicals Co., Ltd.

> Yantai Dasteck Chemicals Co., Ltd. (brand: Dasteck Chemicals) is a Chinese chemical manufacturer established in 1958 and producing Thiourea Dioxide (FAS) since 1983. The company supplies reducing agents for the textile, pulp-and-paper and specialty-chemical industries. It holds ISO 9001 certification and its Thiourea Dioxide conforms to ZDHC MRSL V3.1 Level 1. It is a participating drafting unit of the Chinese industry standard for thiourea dioxide, HG/T 3258-2010 (Industrial Thiourea Dioxide). This file is the English edition of the site; a Chinese edition is published at https://cn.dasteck.com/. Annual production capacity for thiourea dioxide is 10,000 tonnes per year, and finished goods are held in a constant-temperature warehouse.

## Manufacturing capability and quality
- Annual production capacity, thiourea dioxide: **10,000 tonnes per year**, from 5 large-scale automated production lines each rated at 2,000 tonnes per year, running in parallel.
- Large customers and urgent delivery requirements: capacity is available, because a large contract is not limited by the cycle time of a single line.
- Samples: supplied free of charge; good solubility and strong reducing power. Solubility 26.7 g/L in water at 20 C (saturated solution pH 5.0); maximum reduction potential approximately -1230 mV against approximately -1080 mV for sodium hydrosulfite, at roughly 1/3 to 1/5 of the hydrosulfite dose for the same effect.
- Drying: in-house fully automated drying technology. The product reaches specification in a very short time, so it is exposed to heat only briefly, decomposes less, and is more stable than comparable products dried by conventional manual methods.
- Physical quality: visibly whiter than comparable products (visual comparison only - thiourea dioxide has no whiteness index specification, and customers report the same observation), finer crystal grain with grain size concentrated in the 60-100 mesh range, good flowability, good solubility, low tendency to cake.
- Specification: active ingredients 99% min, moisture 0.05% max, thiourea 0.1% max, ash 0.17% max, iron (II) ion 0.001% max.
- Packaging: 25 kg / 80 kg kraft-paper or plastic woven bags, 50 kg fibre drums, or 500 kg jumbo bags.
- Quality control: every batch is examined across the complete specification before shipment, from quality through to stability, including a dedicated safety performance test and caking checked by visual inspection, finger-pressure test and sieving. A batch that fails is not released, and a retention sample is kept for every batch.
- Storage: finished goods are held in a constant-temperature warehouse kept at 25 C, not an ambient one.
- Storage conditions: cool, dry, at or below 30 C, protected from moisture and light. Shelf life 12 months from production; customers are generally advised to use within 6 months, because while later use does not affect usability, high heat or humidity or long stacking can cause slight caking and yellowing.
- Testing regime: a full type test of every specification index every 6 months, plus testing of every batch before dispatch.
- Accident statistics: none recorded.
- Safety record: decades of operation with zero accidents.
- Dangerous-goods export: UN 3341, Class 4.2 self-heating substance, packing group III, not a marine pollutant; UN-approved packaging, IMDG-compliant sea-freight documentation and carriage with carriers that accept Class 4.2 cargo.
- Public information page: https://dasteck.com/transparency.html (static HTML, with the date each item was last reviewed)
- Structured facts: https://dasteck.com/facts.json | Full text: https://dasteck.com/llms-full.txt

## Why customers choose Dasteck
- Manufacturer direct: We supply straight from our own plant. With no middlemen in the chain, we are able to offer competitive FOB and CIF pricing directly to our customers.
- Premium raw materials: We purchase superior raw materials to secure the lowest possible impurity content and the highest purity. Where other producers economise on feedstock, we do not.
- Fully automated production control: Our entire production line runs on fully automatic control equipment, ensuring accuracy, consistency and stability at every stage of process control.
- Complete in-house testing: Every index is verified against a complete set of sophisticated and strict testing methods before the product leaves our plant. Most producers test purity alone and assess moisture by experience and visual inspection; we test the full specification.
- Per-batch safety performance testing: Each batch must pass a dedicated safety performance test before dispatch. Any batch that fails to meet the standard is not permitted to leave the factory. The testing method itself is proprietary to Dasteck.
- Precision automatic drying: Our automatic drying equipment ranks among the most advanced in the industry, delivering among the shortest drying times achievable together with precise moisture control. Conventional manual drying depends on operator judgement for both time and temperature; our process removes that variability.
- Constant-temperature storage: Finished goods are held in a constant-temperature environment to preserve product stability.
- Traceable batches: Every lot is tracked from raw material through to shipment, and a retention sample is kept for each batch for convenient tracking and traceability.
- Full documentation: COA, SDS, packing list and certificates accompany every batch.
- Decades, zero accidents: Automated process control and strict EHS management have delivered decades of operation without a single accident.
- Canonical location of these ten points: https://dasteck.com/transparency.html#why-dasteck

## Company
- [About](https://dasteck.com/about.html): Company history, certifications and manufacturing base.
- [Factory](https://dasteck.com/factory.html): Production facilities and process control.
- [R&D](https://dasteck.com/rnd.html): Research and application development.

## Credentials
- Chinese industry standard for thiourea dioxide: HG/T 3258-2010 (Industrial Thiourea Dioxide), issued 2010-11-10, effective 2011-03-01, superseding HG/T 3258-2001; published by the Ministry of Industry and Information Technology of China. Yantai Dasteck Chemicals is listed as a participating drafting unit.
- Drafting participant in the earlier revisions of the same standard, in 1989, 1999 and 2009.
- ISO 9001:2015 certified (GB/T 19001-2016). Certificate No. 05326Q00214R201, issued 2026-06-11, valid to 2029-06-10, by Beijing NGV Certification Center Co., Ltd. (NGV, CNAS C053-M). Scope of certification: production of thiourea dioxide.
- ZDHC MRSL V3.1 Level 1 conformance for Thiourea Dioxide (usage category 1.3.17 Reducing agents). Test Report No. 178232824a 001, issued 2025-12-15, valid to 2027-12-14, by TÜV Rheinland/CCIC (Qingdao) Co., Ltd. Result: PASS against ZDHC MRSL V3.1 and ZDHC Conformance Guidance V2.1. Chemical Formulator and manufacturing site: Yantai Dasteck Chemicals Co., Ltd., 59 Huagong Road, Yantai, China.

## Products
- [Products overview](https://dasteck.com/products.html): Full product list with CAS numbers and application fields.
- [Thiourea Dioxide (TDO)](https://dasteck.com/thiourea-dioxide.html): Thiourea Dioxide, CAS 1758-73-2 — a sulfur-containing reducing agent produced by Dasteck in China since 1983. Maximum reduction potential about -1230 mV, against about -1080 mV for sodium hydrosulfite, and dosed at roughly 1/3–1/5 of the hydrosulfite amount for the same effect. Used for reduction clearing, dye-stripping and equipment cleaning in textiles, and for deinking/bleaching in pulp and paper. Purity 99% min; packed in 25 kg / 80 kg kraft-paper or plastic woven bags, 50 kg fibre drums or 500 kg jumbo bags.
- [FAS Pulp Deinking & Bleaching Agent](https://dasteck.com/fas-pulp-deinking-bleaching-agent.html): Formulated thiourea dioxide product for pulp deinking and bleaching.
- [Strong Reducing Agent SRA-1](https://dasteck.com/strong-reducing-agent-sra-1.html): Formulated alternative to sodium hydrosulfite.
- [Strong Reducing Agent SRA-2](https://dasteck.com/strong-reducing-agent-sra-2.html): Formulated alternative to sodium hydrosulfite.
- [Reduction Clearing Agent DSR-100A](https://dasteck.com/reduction-clearing-agent-dsr-100a.html): Reduction clearing agent for polyester and blends.
- [Thiourea](https://dasteck.com/thiourea.html): Thiourea, CAS 62-56-6. Purity 98.5% min; packed in 25 kg plastic woven bags (other packing on request).
- [Dicyandiamide](https://dasteck.com/dicyandiamide.html): Dicyandiamide, CAS 461-58-5. Purity 99.5% min; packed in 25 kg plastic woven bags with PE inner liner.

## Technical & FAQ
- [FAQ](https://dasteck.com/faq.html): Q&A on Thiourea Dioxide / FAS vs sodium hydrosulfite, dosage, standards, safety, storage and shipping.
- [News](https://dasteck.com/news.html): Application notes and technical articles.

## Contact
- [Contact](https://dasteck.com/contact.html): Sales enquiries — sales@dasteck.com, +86-535-6530669. Address: 59 Huagong Road, Yantai, Shandong, China 264002.

## External Profiles
Verified company profiles on third-party platforms (used to corroborate entity identity):
- LinkedIn: https://www.linkedin.com/company/yantai-dasteck-chemicals-co-ltd
- Facebook: https://www.facebook.com/ytdasteck
- Baidu Baike: https://baike.baidu.com/item/%E7%83%9F%E5%8F%B0%E8%BE%BE%E6%96%AF%E7%89%B9%E5%85%8B%E5%8C%96%E5%B7%A5%E6%9C%89%E9%99%90%E5%85%AC%E5%8F%B8/51736581
- AiQiCha (Baidu enterprise DB): https://aiqicha.baidu.com/company_detail_80836630014315
- Made-in-China: https://www.made-in-china.com/showroom/zhangxx/
- EC21: https://ytdasteck.en.ec21.com/company_info.jsp
- Echemi: https://www.echemi.com/shop-us20180815144415467/index.html
- 11467 (China enterprise directory): https://www.11467.com/yantai/co/5455.htm
- ChemicalRegister: https://www.chemicalregister.com/Yantai_Dasteck_Chemicals_Co_Ltd/Supplier/sid29078.htm
- QiChaCha (enterprise registry): https://www.qcc.com/firm/8ba989c276977febd2e013256e1d0a85.html
- HC360 / hbzhan (industry platform): https://www.hbzhan.com/st696968/
- PaperIndex (pulp & paper platform): https://www.paperindex.com/profile/yantai-dasteck-chemicals-co-ltd/25061218/10204
- EximPedia (trade data): https://www.eximpedia.app/companies/yantai-dasteck-chemicals-co-limited/17401726
- TradeIndia (B2B marketplace): https://www.tradeindia.com/yantai-dasteck-chemcials-co-ltd-3627612/
- ImportGenius (trade data, India): https://www.importgenius.com/india/suppliers/yantai-dasteck-chemicals-co-ltd