O2 Clean Breathing Inc

O2 Clean Breathing Inc. is a Chelsea, MA company built around air duct cleaning, mold remediation and water damage restoration; the company says it works Boston and the wider Boston area. One name comes up almost every time a customer describes the work: Bairo, the owner, whom reviewers credit by name job after job rather than crediting a faceless crew. The review record backs that up in volume — 5 stars from 66 Google reviews, 4.9 stars across 75 Thumbtack ratings, and clean small samples on Angi and HomeAdvisor, spanning 2022 through 2026 with 16 of the most recent reviews landing in the last six months and none of them negative. Recent write-ups describe specific jobs rather than generic praise: mold pulled from an attic and basement alongside a full HVAC and duct cleaning, mini-split units another company had cleaned "completely incorrectly" and left moldy that Bairo was called back in to fix properly, and baseboard heaters a customer said "apparently hadn't been touched in 20+ years" cleaned along with a full-home vacuum. In Revere, a customer hired O2 for a vapor barrier, HVAC cleaning, insulation and crawlspace seal on a time-sensitive job, and said the price beat every other quote received. One reviewer, writing in Spanish, praised a careful, fully explained central-air cleaning. O2 states certifications from NORMI — mold assessment and sanitization — and from the Professional Mold Inspection Institute and CMRI. Its Better Business Bureau profile carries an A+ rating, though the company isn't BBB-accredited, and BBB lists a Massachusetts BBRS contractor license for the business (#210639), set to run through the end of 2027 — both are BBB's and the company's own claims rather than something an outside registry has independently confirmed here. There isn't much in the record to flag: every platform's recent activity runs positive. Reviewers do repeatedly describe Bairo explaining and documenting the work step by step as it happens, which is worth asking for directly on a bundled job. This is a solid call for a mold problem — especially one another company mishandled — or a duct and dryer-vent system that's never been properly cleaned; for a larger combined job like insulation plus remediation, ask to see current license and certification documentation before booking.