Swedish media are reporting (here and here) that Northvolt encouraged employees at their Skellefteå plant to continue to work in areas affected by a leak of ammonia, well in excess of legal exposure limits, on the basis that they had PPE which could tolerate the higher levels. I haven’t seen much reporting in English on this, but if the reporting is even remotely correct then this is concerning.
Briefly:
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Ammonia levels up to 155 ppm were measured, and the maximum exposure limit set by the Swedish Work Environment Authority is 50 ppm
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The company reportedly encouraged workers to continue working in affected environments with personal protective equipment (PPE) and an internally-determined exposure limit of 500 ppm, on the basis that the PPE could handle this level
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Northvolt argues that safety is its top priority, that it is following the Work Environment Authority’s guidelines and implies that the media is encouraging workers to be concerned
My strictly personal thoughts:
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The 50 ppm level reported is the korttidsgränsvärde (short-term limit), which for the special case of ammonia applies to 5 minutes of exposure (normally, it is 15 minutes). For an 8 hour day, the legal limit is, in fact, 20 ppm (source).
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The US EPA sets the Acute Exposure Guideline level 2 (AEGL-2) limit for ammonia at 160 ppm for a 60 minute exposure, and 110 ppm for a 4 hour exposure. This is the level above which a person would be expected to be at risk of irreversible health effects and/or an impaired ability to escape - if exposed a single time in their entire life. Northvolt indicate the maximum level they measured was 155 ppm.
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The US NIOSH sets the immediate danger to life and health (IDLH) level at 300 ppm. The AEGL-3 for an 8 hour duration (life-threatening level) is 390 ppm. Both are substantially below Northvolt’s ‘internal limit’
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The reporting suggests that workers were encouraged to work as normal, with PPE, despite the elevated levels. If true, this bothers me. PPE is the last resort after all other possible risk mitigations. Adopting PPE in this situation would be acceptable if the work was to fix the leak and reduce the ammonia levels. Otherwise, established practice would be to stop work until the root cause is solved and levels brought well below the legal limits
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Even allowing work to continue with PPE under these conditions carries substantial risk. It assumes the PPE is used correctly, fits correctly, is in good condition, that the workers can use it correctly - at levels which mean serious harm if these assumptions are not correct
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Ammonia is corrosive and damages the nerves in the nose (and the lungs), causing people to become less sensitive to its smell over time
Northvolt’s responses to these reports don’t reassure me. My impression is that production comes first, not safety, and I’m not sure using PPE as a workaround while there is a corrosive gas leak in the building is even compliant with legal requirements let alone best practice. I recognise that the company receives a lot of media attention, and could argue the attention is disproportionate, but Northvolt is in the news increasingly for all the wrong reasons. A cursory look at Swedish social media shows that their public image is taking a beating right now. I want to see them succeed, but their approach to safety, public relations, and working conditions has to match the lofty ambitions and vision they have for industrial transformation.