Post-leak mold investigation and remediation oversight for a BSL-2 research facility
Anonymized — private biotech R&D company, single-tenant building
The challenge
A chilled water line leak above a BSL-2 lab ceiling went undetected over a weekend. By Monday, two employees had reported respiratory symptoms and visible water staining had spread across multiple ceiling tiles. The employer had an IIPP obligation to investigate reported hazards — but no protocol for mold assessment, no remediation contractor on file, and active research that couldn't be shut down indefinitely.
6
Indoor air sampling locations across affected zones
3
Mold genera identified including Cladosporium and Penicillium
11
Days from initial assessment to post-remediation clearance
0
Recurrence findings at post-remediation verification
What we did
- 1
Phase 1 — visual and moisture survey: pin/pinless moisture mapping of ACT, drywall, and subfloor; IR thermography of suspect wall cavities; HVAC supply/return inspection to assess cross-contamination risk.
- 2
Phase 2 — air sampling: spore trap (Air-O-Cell) samples at six indoor locations plus one outdoor control, collected before remediation began to establish baseline and scope.
- 3
Phase 3 — surface sampling: tape lifts on suspect ceiling tiles and bulk sampling of removed ACT to identify genera and inform remediation approach.
- 4
Wrote the remediation scope of work for the abatement contractor: containment boundaries, negative pressure requirements, PPE, and disposal procedures per IICRC S520.
- 5
Provided on-site oversight during remediation and conducted post-remediation verification (PRV) air sampling to confirm clearance before the lab reopened.
Before & after
Before
- Visible water staining across ceiling tiles with unknown moisture extent
- Two employees with active respiratory symptoms and no documented employer response
- No mold assessment, no remediation scope, no contractor engaged
- Research operations paused with no timeline for return to work
After
- Full moisture map and air/surface sampling completed within 48 hours of engagement
- Remediation scope delivered to contractor; work completed under containment with lab operations partially maintained
- Post-remediation verification passed; affected lab area cleared for reoccupancy in 11 days
- Complete documentation package delivered — assessment, remediation records, PRV — satisfying IIPP and insurance carrier requirements
The outcome
Lab cleared for full reoccupancy 11 days after initial assessment, with zero PRV exceedances.
Employee symptom reports resolved; documentation package provided to HR and occupational health for recordkeeping.
Identified a secondary moisture intrusion point in the HVAC return plenum that the original leak response had missed — remediated before it became a second event.