WatchGas SST1 2 Year SO2 Gas Detector SST1-S-24

Not every SO2 monitor needs to give you a number. Sometimes the job just needs a badge that alarms when sulfur dioxide exceeds a compliance threshold — no calibration schedule, no battery replacement cycle, no configuration menu to train workers on. That's what the SST1 Limited-Life line is for.

You'll smell sulfur dioxide before you can see it — but by the time you're smelling it, you may already be at or above OSHA's exposure limit. SO2 has a pungent, unmistakable odor that most workers can detect between 0.5 and 3 ppm. OSHA's permissible exposure limit is 5 ppm as an 8-hour time-weighted average. The concentrations where you can smell SO2 and where you're already at the exposure limit overlap. Smell isn't a reliable measure of what you're breathing.

The WatchGas SST1 2-Year SO2 gas detector is an alert-only monitor: no digital ppm display, factory-set alarm setpoints anchored to OSHA's PEL, non-serviceable, and no maintenance required. Activate it once, and it runs continuously for two years — no calibration, no battery replacement, no charging — alarming immediately when SO2 exceeds the factory-set thresholds. At $230, it's the shortest-commitment, lowest-cost SO2 monitor in the SST1 line — designed for jobs that finish inside two years.

Two ways to run SO2 monitoring — pick the one that fits your job.

The SST1 SO2 line covers two tiers:

• Full-instrument, serviceable: the WatchGas SST1-S serviceable SO2 monitor — digital ppm readout, configurable low/high/TWA/STEL alarms (defaults ship at 2 ppm / 5 ppm, aligned to the NIOSH REL), replaceable sensor cell at end-of-life. Higher upfront cost; lowest lifecycle cost for fleets in continuous multi-year service; the right choice if your exposure program is NIOSH-aligned or stricter than OSHA.
• Alert-only, 2-year lifespan (this SKU): $230, factory-set alarms anchored to OSHA's PEL, non-serviceable, two-year operational life. Lowest upfront cost; ideal for shorter-duration commitments like refinery turnarounds, seasonal mill campaigns, mutual-aid emergency response, single-project contractor deployments, or training programs.

Factory-set alarm thresholds, anchored to OSHA's permissible exposure limit for sulfur dioxide: Low 5 ppm matches OSHA's PEL of 5 ppm 8-hour TWA under 29 CFR 1910.1000 Table Z-1. High 10 ppm provides an acute warning at 2x the OSHA PEL — a signal to leave the area immediately rather than continue working through a low-alarm condition. Because the alarms are factory-set (not user-configurable), you don't need to train workers on setpoint programming, and there's no risk of a monitor being accidentally reconfigured away from a compliant threshold in the field. If your facility runs against the stricter NIOSH REL (2 ppm TWA + 5 ppm STEL) or the ACGIH TLV-STEL (0.25 ppm), the full-instrument SST1-S is the right choice — its low/high/TWA/STEL alarms are all configurable.

Who buys the SST1-S-24 for SO2 monitoring:

• Refinery turnaround contractors on short-duration deployments — hydrotreating unit outages, sulfur recovery unit maintenance, sour crude handling projects
• Pulp and paper mill contractors on Kraft-process campaigns or on-site sulfur recovery inspections
• Metal smelting contractors on short-term projects at copper, zinc, or lead smelting facilities
• Sulfuric acid manufacturing plant maintenance contractors on turnarounds
• Coal-fired power plant contractors during boiler outages and stack maintenance
• Mining and mineral processing contractors on sulfide ore roasting or smelting projects
• Mutual-aid emergency response teams needing low-cost grab-and-go SO2 inventory for industrial fire response and chemical release response
• Municipal hazmat teams needing occasional SO2 detection capability at industrial incident scenes
• Volcanology researchers and geothermal facility auditors on temporary assignments
• Training programs using disposable monitors for teaching — shorter lifespan means faster inventory turn at lowest unit cost

Sensor and alarm specifications:

PK Safety services the full WatchGas SST line with factory-trained technicians in-house. The SST1 Limited-Life alert-only monitors don't require calibration during their fixed lifespan (the whole point of the design), but if you're mixing them with a fleet of the serviceable SST1 line — or with any other gas detectors — PK Safety supports the full WatchGas SST platform, plus BW/Honeywell (Factory Authorized Service Center), RKI, and RAE Systems. Call us at 800.829.9580 to talk through your SO2 monitoring workflow with someone who understands both tiers of the SST1 SO2 line and can help you pick the right one for the job.

Important lifecycle notes:

• Warranty: One year shelf life (unactivated) then two years from activation date. Your operational clock starts the moment you turn the monitor on for the first time.
• Once activated, the monitor cannot be shut down. It continues to run for its full two-year lifespan, and cannot be returned or shipped once activated (an alarm during transit is possible). Unactivated monitors can be returned normally.
• Not resellable after activation. Buy for a specific worker or crew; the monitor stays with them.
• The display shows MM and DD — months and days remaining before the monitor expires — not the current gas concentration.

Part Number: WG01-SST1-S-24 — SST1-S-24 SO2 0–100 ppm 2-year fixed life (sulfur dioxide)

Frequently Asked Questions

Not sure which SST1 SO2 tier fits your workflow? Call PK Safety at 800.829.9580. A person who knows the serviceable-vs-alert-only choice will pick up.