Refining
SK Energy and S-Oil operate refineries in Ulsan; S-Oil's Onsan refinery had about 650,000 barrels per day in 2016.
Ulsan is a south-east coastal industrial city of about 1.1 million people, with refineries, a petrochemical complex and the world's largest shipyard. Process plants, tank farms and shipyard work create extensive Zone 1 and Zone 2 areas. If you are specifying an intrinsically safe mobile phone for Ulsan, this page covers the markings, the approvals and the current certification status of the IS-04Z1.
Pre-launch · certification in progress · Launching Q4 2026
Short answer. The SAMS IS-04Z1 is the intrinsically safe smartphone covered here for Ulsan: pre-launch, designed for Zone 1 and Zone 21 (marking target Ex ib IIC T4), with certification in progress and no certificate issued.
Current position: certification in progress, nothing issued, launch targeted for Q4 2026. 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 |
|---|---|---|
| Level of protection | ia, ib or ic matched to the zone | ib, for Zone 1 |
| Entity parameters | Uo, Io and Po within the device limits | Published with the certificate |
| Accessories | Chargers and cases certified with the device | Defined at certification |
| Where it applies | Ulsan: Refinery process units, Petrochemical plants, Tank farms | Classified by the site operator |

An intrinsically safe Android smartphone designed for Zone 1 and Zone 21 hazardous areas in Ulsan. It is pre-launch: IECEx, ATEX and NEC 500 certification is in progress ahead of the Q4 2026 launch.
The companies on site and the hazardous-area types a handset is likely to meet there.
SK Energy and S-Oil operate refineries in Ulsan; S-Oil's Onsan refinery had about 650,000 barrels per day in 2016.
S-Oil's Shaheen petrochemical project was planned for completion by 2026, bringing commissioning crews.
S-Oil is scheduled to complete the Shaheen Project, one of the world's largest petrochemical facilities with an investment of nine trillion won, by 2026, adding new process areas in Ulsan.
Ulsan is described as South Korea's industrial powerhouse, hosting the world's largest automobile assembly plant, the world's largest shipyard and the world's third-largest oil refinery, which is owned by SK Energy.
Ulsan has more than 1.1 million residents and the highest GDP per capita of any region in South Korea, at about 65,352 dollars in 2020, with a deep pool of industrial technicians.
The SK Energy refinery has a capacity of 840,000 barrels a day, and a slightly smaller 669,000 barrel a day S-Oil refinery is also in the city, so two very large refineries operate side by side.
Intrinsic safety limits the electrical and thermal energy in a circuit so that neither a spark nor a hot surface can ignite a gas or dust atmosphere, even when a fault occurs. The ib level, used for Zone 1, tolerates one fault. It is the usual way to make a handheld device that a worker carries continuously through a hazardous area.
The IS-04Z1 is designed on this principle for Zone 1 and Zone 21 (marking target II 2 G Ex ib IIC T4). Intrinsic safety is a design basis, not a certificate: certification is in progress and none has been issued yet.
In Ulsan. Refinery rounds, petrochemical turnarounds and shipyard tank checks all call for photographs, readings and permits in classified areas. A handheld intrinsically safe phone is intended for those tasks, subject to certification in progress and each operator's permits. Commissioning crews on new projects add to demand.
A short checklist for anyone writing or reviewing the specification, with the IS-04Z1 status against each point.
Not yet. The IS-04Z1 is pre-launch and its certification is still in progress ahead of a Q4 2026 launch. No unit goes into a classified area before the certificate covering it exists. The datasheet, the certification schedule and safe-area evaluation units are available now.
SAMS has not published a price. Any figure you are offered for an uncertified Ex phone should be treated with caution; written indicative pricing is available for a defined quantity and site.
The circuits are designed to limit energy so a spark or hot surface cannot ignite a gas or dust atmosphere, even with one fault (level ib, Zone 1). Certification of that design is in progress.
Likely candidates are refinery process units, petrochemical plants, tank farms, shipyard tank and cargo-space work. 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.
Summers are hot and humid with heavy rain from April to September, and winters are cold but dry, with a January mean around 2 degrees. Typically users want good ingress protection, battery performance in cold weather, and cleaning routines in coastal air.
Hydrogen is in a more demanding gas group than most hydrocarbons, and Ulsan has 188 km of hydrogen pipelines and a green-hydrogen town project. Where hydrogen is present, operators typically specify the gas group, so check what the site requires before selecting devices.
Purchasing is normally handled by the operator or its maintenance contractors, and permits follow the operator's own rules. SAMS has appointed no distributor. Ask the operator whether contractors may bring their own devices, and confirm with the site operator.
More on Ulsan, and on other places in South Korea.
Send the site, zone and gas group and roughly how many handsets. We reply by email with the datasheet and the certification schedule.
Tell us the zone, gas group and operator. We will send the datasheet and the certification schedule.