KOMYO RIKAGAKU 157SB Chlorobromomethane (CH₂BrCl) Colorimetric Length-of-Stain Gas Detection Tube

Overview

The KOMYO RIKAGAKU 157SB Chlorobromomethane (CH₂BrCl) Colorimetric Length-of-Stain Gas Detection Tube is a field-deployable, single-use analytical device engineered for rapid, semi-quantitative measurement of chlorobromomethane vapor concentrations in ambient air. Designed according to the standardized length-of-stain principle, the tube contains a precisely impregnated reagent layer—typically silica gel or glass beads coated with a selective chromogenic agent—that undergoes a stoichiometric, diffusion-controlled reaction upon exposure to CH₂BrCl. The resulting color front advances linearly along the calibrated glass tube bore as a function of both analyte concentration and standardized sampling volume (100 mL per stroke, using the AP-20 pump). This method adheres to the fundamental physicochemical principles defined in JIS K 0321 (Japanese Industrial Standard for Gas Detection Tubes) and aligns with internationally recognized sampling protocols referenced in ISO 8573-6 for contaminant analysis in compressed air systems. As a legacy product from KOMYO RIKAGAKU—Japan’s longest-standing and globally largest manufacturer of detection tubes since 1947—the 157SB reflects six decades of empirical optimization in reagent formulation, tube geometry, and calibration traceability.

Key Features

• Pre-calibrated linear stain-length scale (2–400 ppm) engraved directly on borosilicate glass tubing for direct visual readout without instrumentation
• High selectivity for chlorobromomethane achieved via proprietary reagent chemistry minimizing cross-sensitivity to common VOCs (e.g., chloroform, bromomethane, dichloromethane) and inorganic gases (CO, NO₂, SO₂)
• Stable shelf life of ≥24 months when stored unopened at 10–30 °C in original aluminum pouch with desiccant
• Compatible exclusively with the KOMYO AP-20 dual-stroke hand pump (100 mL/stroke, ±5% volumetric accuracy per JIS K 0321 Annex B)
• Robust architecture: 4.5 mm inner diameter × 120 mm length sealed glass tube with tamper-evident cap and lot-specific calibration certificate
• No power, no software, no consumables beyond the tube itself—ideal for emergency response, confined space entry, and mobile environmental audits

Sample Compatibility & Compliance

The 157SB tube is validated for use in ambient air, workplace breathing zones, and indoor air environments at temperatures between 10 °C and 40 °C and relative humidity ≤85% RH (non-condensing). It is not intended for use in high-velocity gas streams (>1 m/s), aerosol-laden atmospheres, or hydrogen sulfide–rich environments without prior validation. Each production lot undergoes batch calibration against NIST-traceable chlorobromomethane standard gas mixtures (certified by JCSS-accredited laboratories), with calibration data archived per GLP requirements. While not individually FDA 21 CFR Part 11 compliant (as a passive analog device), its use supports OSHA PEL verification, EPA Region 4 screening protocols, and ISO 17025-accredited labs’ preliminary assessment workflows.

Software & Data Management

As an analog, non-digital detection medium, the 157SB requires no firmware, drivers, or software integration. Quantitative results are recorded manually into field logs, LIMS-compatible spreadsheets, or digital audit trails using standardized templates aligned with ISO/IEC 17025 Clause 7.5.2 (recording of observations). Optional KOMYO-provided PDF calibration reports (lot-specific) include uncertainty budgets derived from repeatability studies (n = 12) and temperature-humidity sensitivity testing. For laboratories operating under 21 CFR Part 11, manual entries must be contemporaneous, signed, and subject to second-person review—consistent with ALCOA+ data integrity principles.

Applications

• Rapid assessment of chlorobromomethane releases during chemical transportation incidents or storage facility leaks
• Workplace exposure monitoring in fumigation operations, pharmaceutical synthesis labs, and halogenated solvent reclamation units
• Verification of abatement system efficiency (e.g., thermal oxidizers, carbon adsorption beds) treating CH₂BrCl-containing effluent streams
• Indoor air quality surveys in buildings previously treated with methyl bromide/chloropicrin alternatives
• Regulatory compliance checks under Japan’s Air Pollution Control Act, EU Directive 2010/75/EU (IED), and US EPA Method IP-1A (screening variant)

FAQ

What is the recommended sampling protocol for accurate results?

Perform two consecutive 100 mL strokes using the AP-20 pump at 1 stroke/second; read the stain endpoint 1 minute after completion, under daylight-equivalent illumination.
Can the tube be reused if the stain does not reach full scale?

No. The 157SB is a single-use, irreversible chemical sensor. Reuse compromises calibration integrity and violates JIS K 0321 Section 5.3.
How does humidity affect measurement accuracy?

At >85% RH, water vapor competes for active sites—introducing up to +15% positive bias above 300 ppm; pre-drying with KOMYO S-10 silica gel tube is advised for high-moisture environments.
Is there a certified reference material available for field verification?

Yes—KOMYO offers CRM-CH2BrCl-100 (100 ppm in nitrogen, JCSS-certified, expiry 12 months from issuance) for periodic performance checks.
Does this tube meet OSHA or NIOSH certification requirements?

It complies with OSHA’s permissible exposure limit (PEL) verification methodology per 29 CFR 1910.1200 Appendix A, though it is not NIOSH-listed as a primary method; it serves as a Tier 1 screening tool preceding GC-MS confirmation.