Expansion
S-Oil's Shaheen petrochemical project was planned for completion by 2026, bringing commissioning crews.
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. Ulsan has a monsoon-influenced humid subtropical climate, with monthly means from 2.0 degrees Celsius in January to 25.9 degrees in August and high rainfall from April to September. This page explains what to look for in an explosion proof mobile phone for Ulsan, 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 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. Operator approval runs on its own timeline. Certification status. Place facts reviewed October 2026.
| Check | What to look for | IS-04Z1 today |
|---|---|---|
| Protection concept | Flameproof (Ex d) or intrinsic safety (Ex i) | Intrinsic safety, level ib |
| Zone suitability | Zone 1 gas and Zone 21 dust | Design target for Zone 1 and 21 |
| Certificate | Number, issuing body and schedule of conditions | In progress; not issued |
| 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.
A short profile of the site and the kinds of classified area that matter for portable equipment.
S-Oil's Shaheen petrochemical project was planned for completion by 2026, bringing commissioning crews.
HD Hyundai Heavy Industries builds tankers, LNG carriers and FPSOs at Ulsan and merged with HD Hyundai Mipo in 2025.
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.
Ulsan is the corporate base of the Hyundai group, and SK Energy and S-Oil also operate there, so supplier registration usually runs through each company's own vendor process.
The Ulsan Green Hydrogen Town project had laid 188 km of underground pipelines by October 2024 to carry hydrogen, a by-product of petrochemical complexes, to the city centre.
“Explosion proof” is the phrase most buyers use for equipment that may be taken into a classified hazardous area. Strictly, it covers several protection concepts: a flameproof enclosure (Ex d) contains an internal explosion, while intrinsic safety (Ex i) limits electrical energy so that an ignition cannot start. Phones are normally intrinsically safe, because a flameproof handset would be too heavy to carry all shift.
The IS-04Z1 uses intrinsic safety, with a marking target of Ex ib IIC T4, and is designed for Zone 1 and Zone 21. It is pre-launch, certification is in progress and no certificate has been issued.
In Ulsan. In an Ulsan refinery or yard, explosion-proof is a casual label. Flameproof Ex d suits fixed equipment, while a handheld phone in process areas or a vessel tank relies on intrinsic safety. The IS-04Z1 is designed around that concept, with certification in progress and each operator's rules applying.
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.
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.
It is intrinsically safe (marking target Ex ib IIC T4), which is the usual way to make a phone for hazardous areas. It is not a flameproof (Ex d) design, and certification is still 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.
Related guides for Ulsan and for South Korea.
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.