A testing laboratory has a problem an ordinary warehouse never faces: the building itself gets audited. Accreditation assessors inspect walls, floors, and airflow as part of judging technical competence, and biosafety officers inspect the same surfaces against a different checklist. Modular sandwich panels are widely used for this work because the surfaces are flat and the joints can be closed tightly, but a wrongly specified panel adds audit findings instead of removing them.
This guide covers what the governing references actually require, which panel specifications answer those requirements, and the construction details that most often end up in an assessor's report.
The Term BSL-2 Has Already Been Replaced Internationally
This is the part most specifications miss. The World Health Organization published the fourth edition of its Laboratory Biosafety Manual on 21 December 2020, and that edition dropped the BSL-1 to BSL-4 ladder used in the third edition. In its place WHO uses three tiers of control: core requirements, heightened control measures, and maximum containment measures.
According to the summary of changes prepared by ABSA International, topics previously discussed as BSL-2 and BSL-3 now sit under heightened control measures, while BSL-4 becomes maximum containment measures. The change is not cosmetic. The fourth edition makes risk assessment the deciding input rather than a fixed level label.
The practical consequence for a building owner is direct. There is no single room specification that automatically applies just because a laboratory calls itself BSL-2. What decides the build is the biological agent handled, the procedures used, and the laboratory's own risk assessment. Two facilities that both describe themselves as BSL-2 can legitimately need very different air systems.
The BSL-2 label remains in common use across Indonesia because national regulation and market habit have not followed the WHO shift. Using it as everyday shorthand is fine, as long as the building specification is not copied wholesale from a generic checklist.
The Room Requirements Used as a Reference in Indonesia
The most detailed Indonesian reference for BSL-2 rooms remains Minister of Health Decree No. HK.01.07/MENKES/4642/2021. Its original scope is specific, covering laboratories performing COVID-19 NAAT testing, but its list of room requirements is widely used as a practical baseline by designers and contractors.
For building elements, that decree asks for the following, among others:
- A laboratory room large enough to work in and separated from public areas within the building.
- Separation of infectious and non-infectious rooms, with a label on every room door.
- Doors that can be locked or have restricted access, and windows that close tightly.
- Floors that are strong, waterproof, free of gaps or grout lines, preferably epoxy coated, with no square corner between floor and wall.
- Walls that are not rough, are water resistant, and are easy to clean.
- Adequate lighting with fixtures that do not hang from the ceiling.
- A handwashing sink near the room exit door.
- Directional airflow with filtration on the exhaust or HVAC side.
Note the wording on directional airflow. In that document, filtered directional airflow is recommended rather than an absolute obligation for every BSL-2 room. A great deal of published material states flatly that BSL-2 laboratories must run at negative pressure; the claim is firmer than its source.
On the quality side, laboratories pursuing accreditation are also bound by SNI ISO/IEC 17025:2017 clause 6.3, which requires facility and environmental conditions to be suitable for laboratory activities and not to adversely affect the validity of results. That clause names no wall material at all, but it does require environmental conditions to be monitored and recorded. Stable temperature and humidity become a structural requirement rather than a comfort item.
Panel Specifications for Laboratory Walls and Ceilings
Three panel properties decide the outcome: a surface that cleans easily, resistance to disinfectants, and joints that actually close.
For core material, the choice usually narrows to three families. PIR cores give the highest insulation value per unit of thickness and suit tightly conditioned rooms or spaces adjoining low-temperature areas. Rockwool cores are chosen when fire compartmentation is a requirement, for instance a solvent store. EPS cores remain reasonable for low-risk support areas such as clean corridors, dry reagent stores, or changing rooms.
For facings, laboratories that are wiped down routinely with alcohol, sodium hypochlorite, or hydrogen peroxide should use PVC-laminated steel or a coating system tested against chemical exposure. Standard roofing paint chalks and dulls after a few months of routine cleaning, and a chalked surface holds soil rather than releasing it.
Typical panel thickness for laboratory partitions and ceilings falls between 50 mm and 100 mm. That figure follows span and load, not biosafety tier. A ceiling that must carry filter units, ducting, and technician traffic during maintenance needs a different thickness and support frame from an ordinary partition. For rigid foam cored panels, ask for test data referenced to EN 14509 so strength and thermal conductivity claims can be traced.
The material logic here matches what we set out in our guide to GMP cleanroom sandwich panels, with one important difference: testing laboratories meet aggressive chemical spills far more often than pharmaceutical production rooms do.
The Construction Details That Generate Findings
Failures in modular laboratories almost always occur at joints rather than in the middle of a panel. Several points appear repeatedly in assessor notes:
- The floor-to-wall corner. The decree asks for no corner between floor and wall. Curved coving has to merge into the epoxy layer, not be stuck on after the floor is finished.
- Service penetrations. Every pipe, conduit, and cable passing through a panel needs a permanent seal. Temporary sealant shrinks and leaves a gap behind.
- Window and door frames. Vision panels should sit flush with the wall face on the dirty side so no ledge is left for dust to settle on.
- Junctions with existing structure. In refurbishment work, the meeting point between new panels and old masonry is the most commonly overlooked source of air leakage.
Biosafety cabinet placement also shapes the wall layout. Decree 4642/2021 prohibits placing a cabinet in front of an air conditioner discharge, in front of a door, or in a walkway. Those three prohibitions constrain partition and diffuser positions, so they should be settled before panels are cut rather than afterwards.
A Work Sequence That Saves Time
The sequence that produces the least rework is straightforward: lock the equipment layout first, then route HVAC and utilities, then order panels. Ordering panels before the cabinet and pass box positions are final almost always leads to site cutting, and site cuts leave edges that are difficult to close neatly.
Experience on dry rooms and other controlled areas, described in our article on sandwich panels for EV battery plants and dry rooms, shows the same pattern: layout changes after panel delivery are the single biggest cause of delay. Where a laboratory complex includes hazardous chemical storage, fire compartmentation is covered separately in our guide to fire-rated panels for B3 warehouses.
FAQ
Must a BSL-2 laboratory run at negative pressure?
Not automatically. Decree HK.01.07/MENKES/4642/2021 lists filtered directional airflow on the exhaust or HVAC as recommended for BSL-2 laboratory rooms, not as an unconditional obligation. The WHO fourth edition puts this decision on each laboratory's own risk assessment. Where procedures generate meaningful aerosols, negative pressure is sensible and is often required by the owner regardless. Follow your laboratory's risk assessment rather than the tier label.
What panel thickness is right for laboratory walls?
A range of 50 mm to 100 mm covers most laboratory partition and ceiling needs. The exact figure follows support span, ceiling load, and the insulation target for the room, not the biosafety tier. Ceilings that carry filter units and take technician traffic during maintenance need greater thickness or an added support frame. Ask the supplier for span calculations before fixing a number.
Are EPS panels acceptable in a laboratory?
They are acceptable for low-risk support areas such as corridors, dry reagent stores, or changing rooms. For rooms holding flammable solvents, or rooms that need fire compartmentation, a rockwool core is the better choice. That decision should follow the building fire risk assessment rather than the price per square metre.
Do sandwich panels satisfy ISO/IEC 17025 accreditation?
Clause 6.3 of SNI ISO/IEC 17025:2017 names no particular wall material. What it demands is facility and environmental conditions that are suitable and do not adversely affect the validity of results, with monitoring and records to prove it. Sandwich panels help meet that demand because surfaces clean easily and rooms hold temperature and humidity more steadily, but the material alone confers no compliance.
Primary references: the WHO Laboratory Biosafety Manual, fourth edition and the summary of changes prepared by ABSA International.
