Cazdon Labs
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Helsinki · Uusimaa · physics-led

Indoor air, measured and managed.

Cazdon is a physics-led indoor-air practice for homes and businesses across Helsinki and Uusimaa. We handle statutory radon compliance, instrument-grade air-quality measurement, and air-purifier rental — and we tell you exactly what the numbers mean.

radon & indoor air, measured

Check if you must test Explore air quality
Workplace reference level Bq/m³
0 300 500+

Finland's workplace reference level is 300 Bq/m³ for regular work. [5] WHO advises keeping below 100 Bq/m³ where feasible; risk rises ~16% per 100 Bq/m³. [1]

+16%

lung-cancer risk per 100 Bq/m³ rise [1]

Group 1

human carcinogen (IARC, since 1988) [3]

30,000+

Finnish workers above the reference level [5]

300

Bq/m³ workplace reference level (Finland) [5]

What we do

Four ways we keep your air right

Radon Compliance

Statutory STUK radon measurement, working-hour analysis, and remediation management — filed for you, end to end.

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Air Quality Measurement

A one-off, instrument-grade survey of particulates, CO₂, VOCs, temperature and humidity, with a plain-language report.

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Live Air Monitoring

Networked sensors and a live app dashboard — see your air in real time, with alerts when a threshold is crossed.

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Purifier Rental

Rent right-sized HEPA + activated-carbon units by the month. We size, install, and maintain them. Filters included.

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Why physics-led

A measurement is only as good as the person reading it

Cazdon is run by a physicist. Radon is ionising radiation, and its measurement is a dosimetry problem — placement, integration time, ventilation cycles, and seasonal correction all change the number. We treat your data the way a lab would, and we interpret it honestly: when the maths says you're already compliant, we tell you, even if it means we sell you less.

  • Detector placement and integration handled to STUK's method, so the result is valid
  • Working-hour exposure calculated with STUK's official formula — not guesswork
  • Clear distinction between what filtration can fix and what needs ventilation or structural work
  • Plain-language reports you can hand straight to an inspector

How it works

From first measurement to final sign-off

  1. 01

    Check your obligation

    A 30-second assessment shows whether the law applies to your premises.

  2. 02

    We measure on-site

    Detectors and instruments placed to regulation during the Sept–May season.

  3. 03

    We report & file

    Lab analysis, the 0.9 seasonal correction, and the STUK submission, handled.

  4. 04

    We resolve it

    Working-hour analysis, remediation, or a purifier plan for general air quality.

Questions

Frequently asked questions

Is workplace radon measurement mandatory in Finland?
Yes, in defined cases. Under the Radiation Act (859/2018, §155) employers must measure radon in workspaces that are underground, on air-permeable soil, or on the ground floor in STUK-designated obligation areas. [5] , [7]
Who is responsible — the tenant or the landlord?
The duty to measure occupational exposure falls on the employer occupying the space, even in rented premises. [7] The owner handles the building's structure under separate rules.
Can an air purifier fix a radon problem?
No. Radon is a noble gas; HEPA and carbon filtration target particulates and VOCs, not radon. Radon is controlled by ventilation and structural mitigation. [4] We're upfront about that distinction.
What if we exceed 300 Bq/m³?
Often a one-week working-hour measurement shows real exposure during operating hours is compliant, because ventilation runs during the day. Roughly half of such sites clear without remediation. [6]

Not sure if the law applies to you?

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