Climate
A humid subtropical climate with heavy June to August rain.
GS Caltex concentrates its refining and petrochemical plants at the Yeosu Complex, which covers about 6 million square metres, making the complex a large single-site hazardous-area environment. GS Caltex's Yeosu Complex and Lotte Chemical's Yeosu plant create large Zone 1 and Zone 2 areas. This page explains what to look for in an Ex-proof smartphone for Yeosu, and where the IS-04Z1 stands against that list today.
Pre-launch · certification in progress · Launching Q4 2026
Short answer. The SAMS IS-04Z1 is the intrinsically safe smartphone covered here for Yeosu: pre-launch, designed for Zone 1 and Zone 21 (marking target Ex ib IIC T4), with certification in progress and no certificate issued.
For the record, no certificate exists for the IS-04Z1 today. The programme is under way ahead of a Q4 2026 launch. A buyer's engineering review is separate from the certificate. Certification status. Place facts reviewed October 2026.
| Check | What to look for | IS-04Z1 today |
|---|---|---|
| Ex marking | Group, category, protection concept, gas group, temperature class | II 2 G Ex ib IIC T4 (target) |
| Gas group | IIA, IIB or IIC matched to the area drawing | IIC (target) |
| Temperature class | T-class below the ignition temperature of the gas | T4, 135 °C (target) |
| Where it applies | Yeosu: Refinery process units, Ethylene cracker and polymer plants, Chemical storage tank farms | Classified by the site operator |

An intrinsically safe Android smartphone designed for Zone 1 and Zone 21 hazardous areas in Yeosu. It is pre-launch: IECEx, ATEX and NEC 500 certification is in progress ahead of the Q4 2026 launch.
Who operates there and which kinds of classified area a handset would meet, from the SAMS site research.
A humid subtropical climate with heavy June to August rain.
The Yeosu Complex covers about 6 million square metres, with a mixed feed cracker completed in November 2022 producing 900,000 tonnes of ethylene a year.
The company imports around 80 types of crude from about 30 countries and exported to 57 countries in 2022, so tanker and product shipping through the Yeosu coast is continuous.
The aromatics business started in 1990, with annual capacity of 3.0 million tonnes of aromatics and 180,000 tonnes of polypropylene, so benzene-type vapour hazards exist alongside fuel and olefin units.
GS Caltex has a refining capacity of about 800,000 barrels per stream day, and it operates Korea's largest heavy oil upgrading facility at 275,000 barrels a day, cracking heavy residues into lighter fuels.
Yeosu consists of a peninsula and 365 islands, 48 of them inhabited, midway along South Korea's southern coast beside the Bay of Suncheon, with a population of about 269,000.
“Ex-proof” is shorthand for equipment carrying an explosion-protection marking (the Ex mark) that matches the area it enters. The marking states the protection concept, gas or dust group and temperature class, and it must be backed by a certificate issued by a recognised body, so a phone described as Ex-proof should come with a certificate number you can check.
The IS-04Z1 is designed to carry the marking II 2 G Ex ib IIC T4. That is a target: certification is in progress, no certificate has been issued, and SAMS will publish the certificate numbers when they exist.
In Yeosu. With a mixed-feed cracker producing ethylene, the sheet describes large Zone 1 and Zone 2 areas. Ethylene is usually treated as Group IIB, but mixed streams can include hydrogen, which is IIC. The IS-04Z1 target marking is II 2 G Ex ib IIC T4, not yet issued, and the operator decides.
A short checklist for anyone writing or reviewing the specification, with the IS-04Z1 status against each point.
No. Nothing can be bought or taken into a classified area today: certification is in progress and launch is planned for Q4 2026. What is available now is the datasheet, the written certification schedule and evaluation units for safe-area use.
No price is published. While certification is in progress there is no list price and no committed lead time, and a supplier quoting a firm figure for an uncertified Ex handset is promising something it cannot stand behind. Indicative pre-launch pricing is issued in writing against a stated quantity and site.
The marking target is II 2 G Ex ib IIC T4. It becomes a marking only when the certificate is issued; until then it is a design target.
Likely candidates are refinery process units, ethylene cracker and polymer plants, chemical storage tank farms, marine loading jetties. Which areas are classified, and to what zone, is set by the site operator's own area classification drawings.
Not exactly. Explosion proof is a broad everyday term; intrinsic safety is one protection concept, which limits energy so ignition cannot occur. Flameproof (Ex d) is a different concept that contains an explosion. The IS-04Z1 is intrinsically safe by design.
Refining units, a heavy-oil upgrading facility, an olefins cracker, aromatics and polypropylene plants together create flammable vapour and gas areas, including ethylene and aromatic hydrocarbons. The operator sets zones and gas groups, so ask for classification drawings before bringing devices.
The city has an industrial port coast and rail and road links to Gwangju and other Korean cities, so delivery is feasible, though customs and approvals take time for imported electronics. Confirm lead times with your forwarder and the site's gate rules.
It may. A restructuring plan involving Lotte Chemical's Yeosu operations was approved, and its status could change. Procurement and HSE contacts may be in transition. Confirm requirements with the site operator before sending any documents.
Other guides for Yeosu, other places in South Korea, and the pages behind them.
Tell us what you need to equip and where. The SAMS team answers by email with the datasheet and where each certification route stands.
Send the zone and gas group of your site and we will reply with the datasheet and schedule.