Technical guide · AirPropre expertise

3D printing fumes: beware of invisible emissions

Q: Is PLA safe?

PLA is one of the lowest-emitting filaments, but it still emits ultrafine particles and VOCs, including lactide. Colourants and additives alter these emissions. A PLA printer running for long periods in a small room also warrants a closed enclosure and filtered extraction.

Q: Is an air purifier enough?

A free-standing purifier in the room treats the air once the pollutants have dispersed: the person working near the printer remains exposed to the plume. It can supplement capture at source on the printer enclosure, but never replace it.

Q: My printer has a built-in filter: is that enough?

Built-in printer filters vary widely: some trap only a proportion of particles and contain little or no activated carbon. Check the efficiency of the HEPA filter, the quantity of activated carbon and the airtightness of the enclosure. For intensive or professional use, a dedicated fume extractor is safer.

Q: Should the air be exhausted outside?

In France, INRS favours capture with exhaust to the outside after filtration, and recirculation of air from premises with specific pollution is permitted only if the air is effectively cleaned, with a device that signals any failures. For filament or resin printers, an enclosure connected to a HEPA and activated carbon fume extractor is recommended by CNRS, the FOPH and EPFL, provided the filters are replaced in time. For metal powders (nickel, cobalt), exhaust to the outside is essential: Ineris advises against discharging filtered air into work premises.

Q: How often should filters be changed?

The pre-filter should be replaced as soon as it is clogged, and the combined HEPA and activated carbon filter according to the unit's indicator, and at least once a year for the 3D PrintPRO range. The clogging indicator light does not detect carbon saturation: an odour at the extractor outlet indicates that it needs changing, unless the unit is fitted with a VOC sensor.

Q: Does an FFP2 mask protect you?

A well-fitted FFP2 or FFP3 mask traps particles, not gases: it does not protect against VOCs. Respiratory protection is reserved for occasional tasks (depowdering, filter changes) and does not replace capture at source.

Q: Printing in a classroom: what precautions?

Pupils are more vulnerable and the teacher is exposed all day. Choose PLA or PETG, an enclosed printer, certified low-emission if possible (UL 2904 standard), connected to a filtering fume extractor, and a ventilated room; avoid running prints without extraction during lessons. Liquid resins should not be used with pupils.

Q: Are resin printers more dangerous than filament printers?

The risks are different: resin mainly emits VOCs and exposes the skin to highly allergenic substances, while filament emits more ultrafine particles. In both cases: closed enclosure, filtered extraction with activated carbon and, for resin, nitrile gloves and safety glasses.

Filament, resin, powder or metal: every 3D printing technology releases ultrafine particles, volatile organic compounds or dusts that penetrate deep into the lungs. What French, Swiss and European studies show, what the regulations require, and how to protect yourself.

Assess my situation View filtration solutions

Updated 11 November 2026 · 15 min read · 56 sources cited

1,9 × 10¹¹/min

ultrafine particles emitted every minute by an ABS printer, ten times more than with PLA^{[5, 42]}

59%

of professional users surveyed have respiratory symptoms every week^[47]

216VOCs

different volatile organic compounds identified during filament printing^[48]

−99%

particles at the workstation with an enclosed printer and HEPA-filtered extraction^{[8, 32]}

01The key points in one minute

Four key messages

3D printing is now everywhere: design offices, workshops, schools, fablabs, dental laboratories and even homes. Its emissions, however, remain largely overlooked because they cannot be seen.

Invisible does not mean harmless
A filament printer can emit billions of ultrafine particles per minute without any visible smoke or noticeable odour^[42]. Odour is not a reliable indicator.
All technologies emit
Filament: ultrafine particles and VOCs. Resins: VOCs and allergenic substances. Powders: fine dusts, sometimes metallic and carcinogenic. The profiles differ, but the need for protection remains^{[4, 22]}.
The risk is concentrated near the machine
Exposure is highest in an enclosed, poorly ventilated room close to open printers, and increases with the number of machines and the printing time.
The solution is known and effective
Enclose the printer, capture emissions at source, filter the air (pre-filter, HEPA and activated carbon) and ventilate the room: this is the approach recommended by occupational health and safety bodies^{[2, 13, 19]}.

40%

of the additive manufacturing machines observed in industry had no extraction connected, as did 50% in services and 25% in research: these are the findings of the INRS field survey carried out from 2016 to 2018^{[1, 5]}.

Who is affected?

Primary and secondary schools
Universities and laboratories
Fablabs and makerspaces
Design offices
Dental laboratories
Industrial prototyping
Additive manufacturing production
Home users and makers

02Emission mechanisms

How a 3D printer pollutes the air

Heating a polymer to several hundred degrees never happens without emissions. Part of the material and its additives volatilises, then condenses into particles as it cools.

The heated nozzle: from 190 °C to over 400 °C
This is where the filament melts. A fraction of the polymer, its additives and its colourants degrades and evaporates: the higher the temperature, the higher the particle emissions^{[26, 38]}.
Ultrafine particles (< 0.1 µm)
As they cool, these vapours condense into a vast number of particles of roughly 10 to 50 nanometres, invisible to the naked eye^{[38, 44]}.
Volatile organic compounds (VOCs)
Another part remains in gaseous form: styrene for ABS, lactide for PLA, caprolactam for nylon, aldehydes… More than 200 different VOCs have been identified^{[43, 48]}.
The print head fans
Essential for cooling the part, they also disperse the plume into the room when the printer is not enclosed.
The part and ancillary operations
Off-gassing of parts, sanding, solvent smoothing, washing of resin parts, depowdering, maintenance: according to INRS, these operations can result in higher exposure than printing itself^{[2, 3]}.

Finer than a virus: the size scale

Logarithmic scale (each graduation divides the size by 10). Deposition zones according to the conventions of standard NF EN 481.

Human hair

50 à 70 µm

Printing powders

≈ 15 à 90 µm

PM10 / PM2.5 particles

≤ 10 µm / ≤ 2,5 µm

Bacterium

≈ 1 à 2 µm

Virus

≈ 0,02 à 0,3 µm

Filament printer particles

mostly 10 to 50 nm

100 µm10 µm1 µm0.1 µm0.01 µm

Nose, throat

inhalable fraction

Bronchi

< 10 µm

Pulmonary alveoli

respirable fraction, < 4 µm

Alveoli, passage into the blood

ultrafine, < 0.1 µm

Human hair50 à 70 µm
Printing powders (metal, polymer)≈ 15 à 90 µm
PM10 / PM2.5 particles≤ 10 µm / ≤ 2,5 µm
Bacterium≈ 1 à 2 µm
Virus≈ 0,02 à 0,3 µm
Particles emitted by a filament printermostly 10 to 50 nm

Nose, mouth, throat
inhalable fraction
Trachea, bronchi
< 10 µm
Pulmonary alveoli
respirable fraction, < 4 µm
Alveoli and possible passage into the blood
ultrafine, < 0.1 µm

During a print job

Ultrafine particle concentration in the room over time. Schematic diagram based on published measurements, not to scale.

Open printer, without extractionEnclosed printer, filtered extraction

Start-up peak
Particle emissions generally peak at start-up: nozzle heating and the start of printing^{[25, 27, 44]}.
Continuous emission
After the peak, emissions fall and then stabilise: without capture at source, the concentration in the room remains high for as long as printing continues, a few hours, sometimes several days.
Capture at source
Enclosed printer and HEPA-filtered extraction: 99% fewer particles at the workstation in the benchmark Finnish study^[32].
After stopping
The concentration decreases only slowly: leave the extraction running for a few minutes before opening the enclosure.

03Technologies

Each process has its own emissions

Standard NF EN ISO/ASTM 52900 classifies additive manufacturing into seven process categories. Here are the most common ones, and what they release into the air.

FDM · FFF · material extrusion
Filament deposition
High
A thermoplastic filament is melted in a heated nozzle (190 to 300 °C, higher for engineering polymers) and then deposited layer by layer.
Emissions
From 10⁸ to 10¹² ultrafine particles per minute depending on the filament and temperature, and hundreds of different VOCs (styrene, lactide, caprolactam, aldehydes…).^{[38, 43, 48]}
Critical moments
Start of printing, styrenic and polyamide materials, open printer, several machines in the same room; sanding and solvent smoothing of parts.
SLA · DLP · LCD · vat photopolymerisation
Photopolymer resin
High
A liquid (meth)acrylate-based resin is cured layer by layer by an ultraviolet light source.
Emissions
Few particles, but 4 to 7 times more organic vapours than filament according to INRS: sensitising acrylates, formaldehyde, solvents during washing; parts off-gas for weeks. Major skin risk.^{[1, 12, 31]}
Critical moments
Filling and cleaning the vat, washing and post-curing parts, removing supports, contaminated waste.
PolyJet · MultiJet · material jetting
Material jetting
High
Droplets of photopolymer resin are jetted by print heads and then cured with UV light, with a support material to be removed.
Emissions
Total VOCs among the highest measured across all processes (1.1 to 2.5 mg/m³), allergenic acrylates; possible ozone from UV sources.^{[19, 30]}
Critical moments
Changing cartridges, print head maintenance, removing and cleaning supports.
SLS · MJF · powder bed fusion
Polymer powder
High
A polyamide powder (PA12, PA11) is fused by a laser, or by agents and an infrared lamp, in a heated chamber.
Emissions
Dust levels of 1.4 to 9.1 mg/m³ during post-processing of parts; peaks of more than 100,000 particles/cm³ in a sintering room; high VOCs with MJF.^{[30, 33]}
Critical moments
Loading the machine, depowdering parts, sieving and recycling powder, sandblasting, maintenance.
SLM · DMLS · LPBF · EBM · binder jetting · DED
Metal powder
Very high
A metal powder (stainless steel, nickel or cobalt-chrome alloys, titanium, aluminium) is melted by a laser or electron beam, or bound by a binder.
Emissions
Cobalt OELs (VLEP) exceeded during finishing, respirable nickel up to 3 times the German reference value; up to 3 million particles/cm³ when a machine is opened immediately.^{[6, 23, 29, 35]}
Critical moments
Opening the machine, recovering powder, depowdering, sieving, changing filters, cleaning the chamber, grinding: ancillary tasks cause more exposure than the build itself.

Hazard matrix by process

AirPropre summary based on the sources cited. The actual level depends on the materials, quantities, ventilation and work organisation.

Process	Ultrafine particles	VOCs (gases)	Dusts and powders	CMR metals	Skin allergens	Fire, explosion
Filament deposition (FDM / FFF)	Very high	High	Low	Low	—Negligible	—Negligible
Resin (SLA / DLP / LCD)	Low	High	Low	—Negligible	Very high	Low
Material jetting (PolyJet)	Low	High	—Negligible	—Negligible	High	—Negligible
Polymer powder (SLS / MJF)	Low	Low	Very high	—Negligible	—Negligible	High
Metal powder (laser fusion, EBM, binder)	High	—Negligible	Very high	Very high	High	Very high

LowHighVery high“—”: negligible

04Materials

What each material releases

For the same process, the material makes all the difference. Styrenic filaments (ABS, ASA) are among the highest emitters; PLA emits less, but is not emission-free^{[42, 43]}.

Material	Process · temperature	Main pollutants identified	Point to watch
PLALow to moderate	Filament · 190 to 220 °C	Ultrafine particles (around 10 times fewer than with ABS), lactide (up to 75% of VOCs), methyl methacrylate, formaldehyde peaks^{[18, 28, 40, 42]}	“Bio-based” does not mean emission-free: in the Suva study, the PLA tested even emitted more particles than ABS.
PET, PETGLow to moderate	Filament · 220 to 250 °C	Moderate quantities of ultrafine particles, very low VOCs (5 µg/m³ versus 433 for ABS in the INRS study)^{[4, 8, 24]}	Recommended by INRS as a lower-emission substitute for ABS; particles still need to be captured.
ABS, ASA, HIPSVery high	Filament · 230 to 260 °C	Very large numbers of ultrafine particles, styrene (up to 80% of ABS VOCs), acrylonitrile, aldehydes; parts continue to off-gas styrene^{[1, 42, 45]}	Among the highest-emitting filaments: styrene at 150 to 250 µg/m³ near printers, 20 times the level in an office. Enclosed printer and filtered extraction essential.
Nylon (polyamide)Very high	Filament · 240 to 270 °C	Caprolactam (around 90% of VOCs), particle levels among the highest measured^{[24, 28, 43]}	Highest irritation risk in the Danish assessment: up to 10 times the level considered tolerable at peak in a 20 m³ room.
Polycarbonate (PC)High	Filament · 260 to 300 °C	Ultrafine particles and organic compounds; toxicity observed in human bronchial cells^[51]	High temperatures: increased emissions, extraction essential.
Filled filamentsHigh	Carbon or glass fibres, metal powders, wood	Emissions from the polymer matrix, plus metal particles (copper crystals of 120 to 150 nm measured); fibres and dust during machining^[26]	Sand and machine parts under extraction; few published studies.
PEEK, PEKK, PEI, PPSUHigh	High-temperature filament · 340 to 420 °C	Thermal degradation products, ultrafine particles^[38]	Few published data at these temperatures, even though emissions increase with temperature: enhanced capture at source.
(Meth)acrylate and epoxy resinsVery high	SLA / DLP / LCD, PolyJet	Sensitising acrylates, formaldehyde, photoinitiators, isopropanol vapours during washing; off-gassing of parts^{[12, 31, 39]}	Potent skin sensitisers: nitrile gloves, no skin contact, washing under local exhaust ventilation.
Polyamide powder (PA12)High	SLS / MJF · grain size ≈ 40 to 90 µm	Fine dust during handling, VOCs and particles in the sintering room^{[30, 33]}	Combustible dusts: risk of fire and explosion during handling.
Metal powdersVery high	Laser fusion, EBM, binder, DED · grain size ≈ 15 to 45 µm	Nickel, cobalt, chromium (stainless steel, superalloys, cobalt-chrome), aluminium, titanium, copper; nanoparticles during handling^{[6, 23, 35, 36]}	Carcinogenic and sensitising agents, reactive powders: a specific study is essential.

05Health effects

Where particles go, and what they cause

The finer a particle, the deeper it penetrates into the respiratory tract. Ultrafine particles reach the pulmonary alveoli, where air and blood exchange gases.

Nose, mouth, throat: particles larger than 10 µm
The largest particles are trapped in the upper airways and then cleared. This applies to some printing powders.
Trachea and bronchi: thoracic fraction, less than 10 µm
These particles reach the bronchial tree, where they can cause irritation, coughing and asthma attacks.
Alveoli: respirable fraction, less than 4 µm
Fine particles reach the gas exchange region, from which they are cleared very slowly.
Possible passage into the blood: less than 0.1 µm
Ultrafine particles are deposited in large numbers in the alveoli; in both humans and animals, inhaled nanoparticles have been found in the bloodstream and in the plaques of diseased arteries^[41].

Irritation and discomfort
Irritated eyes, nose and throat, discomfort: effects reported by users, and an irritation risk identified by the Danish Environmental Protection Agency for nylon, PLA and ABS in a small, poorly ventilated room^{[25, 28]}.
Asthma and respiratory diseases
A case of occupational asthma was confirmed in a user of ten ABS printers; 59% of users questioned in a survey report respiratory symptoms every week; one hour of exposure to ABS increases a marker of bronchial inflammation^{[25, 46, 47]}.
Skin allergies to resins
Acrylates and epoxy resins are potent sensitisers: cases of occupational allergic contact dermatitis have been described in 3D printing, even among dental technicians. Never touch uncured resin^{[12, 22, 39]}.
Effects of ultrafine particles
3D printer particles, including those from PLA, cause oxidative stress and inflammation in human bronchial cells and in animals. The researchers' conclusion: they are not harmless and exposure should be reduced^{[49, 51]}.
Carcinogenic substances
Styrene (probable carcinogen since 2019), acrylonitrile (known carcinogen since 2024), formaldehyde, nickel compounds and cobalt from metal powders: several of the pollutants emitted are classified as carcinogenic^{[23, 52, 53]}.
Fire and explosion
Fine metal and polymer powders can ignite or form explosive atmospheres; resin washing solvents are flammable^{[22, 34]}.

06State of knowledge

What the studies say

Since 2013, laboratories and occupational health and safety bodies have been measuring 3D printer emissions. The results converge: emissions are systematic, vary widely depending on the material, and are significantly reduced by enclosure and filtration.

FRFrance

2021 · INRS
Review of all additive manufacturing technologies
ABS: 10⁹ to 10¹¹ particles per minute; resins: 4 to 7 times more organic vapours than filament. 2016-2018 survey: 25 to 50% of machines with no extraction connected, depending on the sector.
Source [1]View (new tab)
2025 · INRS
Filament printing emissions: ABS, ASA, PETG
Total VOCs of 433 µg/m³ (ABS), 124 (ASA) and 5 (PETG). Local extraction reduces concentrations by 95 to 99%: the authors recommend placing printers under extraction.
Source [8]View (new tab)
2021 · INRS and CEA
265 measurements in metal additive manufacturing
Cobalt OELs (VLEP) exceeded in pre-production and finishing; up to 3 million particles/cm³ when a machine is opened immediately, with no peak if one waits around ten minutes.
Source [6]View (new tab)
2021 · Mines Saint-Étienne and INRS
Laser fusion of aluminium powder
1.73 mg/m³ of inhalable dust on the operator during unpacking and cleaning; aluminium and magnesium nanoparticles measured at source.
Source [10]View (new tab)
2023 · Ineris (CaRPE project)
Emissions from metal additive manufacturing
Ducted discharges close to urban background levels, but fugitive emissions during cleaning. Recommendations: H14 rather than H13 final filter, no discharge of filtered air into work premises.
Source [11]View (new tab)
2023 · INRS (technical day)
Current state of prevention
Very high acrylate concentrations measured near resin printers; formaldehyde and VOCs inside the enclosure of an ABS printer. 88% of users are micro-enterprises or SMEs.
Source [7]View (new tab)
2024 · AP-HP, Hôtel-Dieu
A dental technician allergic to methacrylates
Occupational contact dermatitis from (meth)acrylates linked to resin 3D printing: a new source of exposure in dental laboratories.
Source [12]View (new tab)

CHSwitzerland

2016 · Suva
Desktop printer and measurements in offices
Small unventilated room: +2,000 particles/cm³ and methyl methacrylate still detectable 20 h after printing. Emissions doubled (PLA) to quadrupled (ABS) after 7 months of use.
Source [18]View (new tab)
2026 · Federal Office of Public Health
Recommendations for 3D printing
Low-emission printers, closed housing with HEPA or activated carbon filters, separate ventilated room; resins free of TPO, a sensitising photoinitiator harmful to fertility.
Source [19]View (new tab)
2024 · EPFL
Guidelines for 3D printers
Enclosed models, ducted connection or HEPA and activated carbon filtration, 6 to 8 air changes per hour in the rooms; metal powder printers subject to authorisation.
Source [20]View (new tab)

UEEurope

2017 · EU-OSHA
3D printing and additive manufacturing: the implications for occupational safety and health
Hazardous ultrafine particles and VOCs: ventilation advisable with PLA, necessary with ABS; enclose the printer, vacuum up powders, never touch uncured resin.
Source [22]View (new tab)
2017 · IFA / DGUV, Germany
Metal exposure in additive manufacturing
Nickel-based alloys: respirable nickel up to 3 times the German reference value in post-processing, and up to 2 times during manufacturing despite enclosure.
Source [23]View (new tab)
2020 · IFA / DGUV, Germany
Emissions from 7 filaments in a test chamber
From PLA to nylon, particle emissions vary by a factor of 400; they increase with temperature. VOCs below limit values in a ventilated room.
Source [24]View (new tab)
2018 · LMU Munich, Germany
26 volunteers exposed for one hour to an ABS or PLA printer
More than one million particles per cm³ with ABS versus fewer than 6,000 with PLA; marker of bronchial inflammation (FeNO) increased after ABS.
Source [25]View (new tab)
2017 · Danish Environmental Protection Agency
Risk assessment of 3D printers
4 h of printing in 20 m³: caprolactam (nylon) up to 10 times the level considered tolerable at peak; formaldehyde (PLA) 1.9 times. Risk of eye and respiratory tract irritation.
Source [28]View (new tab)
2021 · FIOH, Finland
Technical control of nanoparticles from a desktop printer
Open hood: −30%; enclosure alone: −97%; enclosure with HEPA extraction: −99% particles at the workstation. General ventilation alone is insufficient.
Source [32]View (new tab)
2019 · University of Eastern Finland
Exposures across five printing technologies
Up to 81,890 particles/cm³ on average; high VOCs in material jetting and MJF; 1.4 to 9.1 mg/m³ of dust during post-processing of powder parts.
Source [30]View (new tab)
2022 · University of Eastern Finland
Emissions from photopolymer resins and off-gassing of parts
Sensitising acrylates and formaldehyde; resin parts continue to off-gas for weeks (emissions reduced by 84 to 96% after 28 days).
Source [31]View (new tab)
2019 · Linköping, Örebro, STAMI (Sweden, Norway)
Biomonitoring of operators in metal additive manufacturing
Higher cobalt exposure in operators than in welders; decrease in urinary metals after prevention measures were introduced.
Source [35]View (new tab)
2023 · HSE, United Kingdom
Exposure to metal powders in additive manufacturing
Exposure peaks during manual cleaning and powder transfers; HSE notes an over-reliance on masks: containment is the key measure.
Source [37]View (new tab)
2017 · University of Cassino, Italy
Effect of material and temperature
Ten materials tested, all emitting ultrafine particles (10 to 30 nm), up to 10¹² particles per minute; emissions increase with temperature.
Source [38]View (new tab)

INTKey international studies

2013 · Illinois Institute of Technology
The first study on ultrafine particles from 3D printers
Around 2 × 10¹⁰ ultrafine particles per minute with PLA and 1.9 × 10¹¹ with ABS.
Source [42]View (new tab)
2016 · Illinois Institute of Technology
5 printers, 9 filaments: particles and VOCs
Styrene from 10 to 110 µg/min (ABS, HIPS), caprolactam up to 180 µg/min (nylon), lactide (PLA). Recommendation: filter both gases and particles.
Source [43]View (new tab)
2019 · Georgia Tech, UL Chemical Insights
Particle composition and toxicity
Toxicity observed in vitro and in mice for both ABS and PLA. The authors conclude that these particles are not harmless.
Source [49]View (new tab)
2018 · University of Toronto
Health survey of regular users
59% of the 46 workers surveyed report respiratory symptoms at least once a week; more than 40 h of use per week associated with asthma or rhinitis.
Source [47]View (new tab)
2019 · NIOSH
Emissions and exposures at four workplaces
Ventilated enclosure: 99.7% fewer particles, but only 53% fewer organic compounds: gas filtration is essential.
Source [50]View (new tab)

What the studies show

All technologies emit. Emissions vary by a factor of 10 to 100 depending on the material and temperature. Handling phases (depowdering, washing, sanding, maintenance) often involve the highest exposure. Enclosure combined with filtered extraction eliminates most particle exposure.

What they do not say

Official German measurements found VOCs below the limit values for a properly used desktop printer in a ventilated room, and the volunteer study showed no major acute effect within one hour^{[24, 25]}. The effects of repeated exposure over years, however, remain poorly understood. The message from occupational health and safety bodies: not harmless, and therefore to be controlled.

07Regulatory framework

What the law requires of employers

There is no legislation specific to 3D printing: the general rules on the prevention of chemical risks apply, in France as in Switzerland. Employers have a duty of safety towards their employees, including students and trainees.

FRFrance

Assess the risks and record them in the single risk assessment document (DUERP), Art. R4121-1 of the French Labour Code.
Hazardous chemical agents: eliminate the risk or reduce it to a minimum, primarily through collective measures (Art. R4412-1 et seq.).
Carcinogenic, mutagenic and reprotoxic agents: substitution, closed system or capture at source, regular measurements (Art. R4412-59 et seq.).
Premises with specific pollution: capture as close as possible to the source (Art. R4222-12); air recirculation only if the air is effectively cleaned, with a device that signals any failure of the cleaning system (Art. R4222-14 to R4222-17).
Rooms housing these machines are premises with specific pollution^[2]; dusts with no specific effect have been limited to 4 mg/m³ (inhalable) and 0.9 mg/m³ (respirable) since 1 July 2023 (Art. R4222-10)^[17].
Compliance with occupational exposure limits (OELs; French VLEP)^[16].

CHSwitzerland

Employment Act (LTr) and its Ordinance 3 (OLT 3): health protection, adequate ventilation, capture of harmful emissions.
Accident Insurance Act (LAA) and Accident Prevention Ordinance (OPA): technical and organisational measures against harmful substances.
Workplace exposure limits (Swiss MAK values, VME/VLE) published by Suva^[21].
STOP principle: Substitution, Technical, Organisational, then Personal measures.
MSST Directive: occupational safety specialists to be called in according to the hazards.

UEEuropean Union

Directive 98/24/EC on chemical agents and Directive 2004/37/EC on carcinogens, mutagens and reprotoxic substances.
REACH and CLP Regulations: classification of resins and powders, safety data sheets.
Machinery Regulation (EU) 2023/1230, applicable from 20 January 2027: machinery must be designed to capture or reduce its hazardous emissions.
Standards NF EN ISO/ASTM 52931:2023 (health and safety in metal additive manufacturing) and ISO 27548:2024 (measurement of emissions from desktop filament printers)^{[54, 55]}.

Limit values for the main pollutants emitted

8-hour values in mg/m³ (in brackets: in ppm). France: VLEP^[16], C = binding, I = indicative; Switzerland: VME^[21], (i) = inhalable, (a) = alveolar (respirable). Values as of November 2026, to be checked against the legislation in force before any assessment.

Substance	Source in 3D printing	French OEL (VLEP)	Swiss MAK value (VME)	Classification
Styrene	ABS, ASA, HIPS	100 (23,3) · C	85 (20)	IARC 2A
Acrylonitrile	ABS, ASA	1 (0,45) · C	4,5 (2)	IARC 1 (2024)
1,3-Butadiene	ABS degradation	2,2 (1) · C	4,4 (2)	IARC 1
Formaldehyde	PLA, ABS, resins	0,37 (0,3) · C	0,37 (0,3)	IARC 1
ε-Caprolactam	Nylon (PA6)	10 · I	5 (inhalable)	Irritant
Methyl methacrylate	PLA, resins	205 (50) · C	210 (50)	Skin sensitiser
Methyl acrylate	Resins	18 (5) · C	18 (5)	Skin sensitiser
Nickel compounds	Stainless steel powders, superalloys	0.05 inhalable · 0.01 respirable · C	0,05 (i) · 0,01 (a)	IARC 1
Cobalt and compounds	Cobalt-chrome powders, superalloys	No VLEP (EU value in preparation)	0,05 (i)	Carcinogenic and reprotoxic 1B, asthma
Chromium VI	Fumes from chromium alloys	0,001 · C	0,005 (i)	IARC 1
Ozone	UV sources (material jetting)	0,2 (0,1)	0,2 (0,1)	—
Dusts with no specific effect	Polymer powders, sanding	4 inhalable · 0.9 respirable	10 (i) · 3 (a)	—
Ultrafine particles	All technologies	No VLEP	No VME	—

08Prevention approach

Prevention: in what order to act

The general principles of prevention (Art. L4121-2 of the French Labour Code) and the STOP principle applied in Switzerland set the same order: act first on the source, then on the environment, and finally on the individual.

S
Eliminate or substitute
Choose the lowest-emitting process and material compatible with the intended use, and the lowest possible printing temperature.
T
Enclose the printer
A closed enclosure, kept under slight negative pressure, prevents the plume from dispersing into the room.
T
Capture at source and filter
Connect the enclosure to a fume extractor: pre-filter, HEPA filter for particles, activated carbon for VOCs; or exhaust to the outside.
O
Ventilate and organise
Dedicated, ventilated room, workstations at a distance, opening instructions, filter maintenance, training.
P
Protect people
Nitrile gloves and safety glasses for resins, P3 respiratory protection for powders: as a supplement, never as a substitute.

Good practice

Install printers in a dedicated, ventilated room, away from offices and classrooms
Keep the enclosure closed throughout printing and connect it to a filtering fume extractor
Start extraction when printing starts, keep it running after the end of the cycle, and wait around ten minutes before opening a powder machine^{[6, 9]}
Wash resin parts under local exhaust ventilation, wearing nitrile gloves
Depowder and sieve under extraction, never with a blow gun
Maintain the printer: its emissions increase with wear^[18]
Replace filters according to the manufacturer's recommendations and keep a record of changes
Do not assign people allergic to nickel, cobalt or methacrylates to exposed workstations^[1]
Inform and train users, including students

Common pitfalls

Relying on smell: ultrafine particles are odourless
Relying on a free-standing air purifier in the room: it does not capture at source
An enclosure without extraction: it concentrates emissions and releases them when opened
A HEPA filter alone: it does not trap gases (VOCs)
Activated carbon that is never replaced: once saturated, it traps nothing
An FFP2 mask against VOCs: it filters only particles
Opening the enclosure as soon as printing ends

09Filtration

Effective filtration: three complementary stages

No single filter medium deals with both particles and gases. Filtration suited to 3D printing combines a pre-filter, a HEPA filter and an activated carbon stage.

Inlet
Contaminated air
Ultrafine and fine particles, dusts, gases and odours extracted from the printer enclosure.
Stage 1
Pre-filter
96 % à 2 µm
Traps the largest particles and protects the HEPA filter, extending its service life.
Stage 2
HEPA filter
99,995 % à 0,3 µm
Captures fine and ultrafine particles: filtration must be suitable for trapping nanoparticles. The smallest ones, agitated by Brownian motion, are very effectively trapped by the fibres^{[13, 14]}.
Stage 3
Activated carbon
Adsorbs VOCs and odours in its micropores. Its capacity is limited: it must be replaced before it becomes saturated.
Outlet
Cleaned air
Recirculated into the room or exhausted outside, depending on the pollutants and the applicable regulations.

Efficiencies: Donaldson BOFA manufacturer data for the 3D PrintPRO range^[56].

The difference each measure makes: measured results

Reduction in the number of particles at the workstation compared with general office ventilation alone.

Hood above an open printerextraction without enclosure
−30%
Closed enclosure without extractionenclosure only
−97%
Closed enclosure and HEPA-filtered extractioncapture at source
−99%

Measurements taken in a real office with an ABS printer^[32]. Note: a ventilated enclosure removes 99.7% of particles but only 53% of organic compounds^[50]; this is where activated carbon comes in. A closed enclosure without extraction also releases its pollutants each time it is opened.

Typical installation: enclosure under negative pressure connected to a filtering fume extractor.

Closed enclosure
Factory-fitted cover or add-on enclosure: it contains emissions as close as possible to the source.
Extraction point at the top
Hot emissions rise: the extraction point is placed above the print area, without cooling the nozzle.
Connection hose
As short as possible, with no tight bends, to maintain the extraction airflow.
Filtering fume extractor
Pre-filter, HEPA and activated carbon, with a filter clogging or filter change indicator.
Cleaned air
Recirculated into the room, or exhausted outside for the most hazardous pollutants.
Make-up air inlets
The enclosure remains under slight negative pressure: air comes in, emissions do not get out.

Criteria for choosing a fume extractor

Airflow and suction pressure: Sufficient to keep the enclosure under negative pressure despite the pressure drop of clogging filters.
Particle filtration efficiency: Certified HEPA filter: this is what traps ultrafine particles.
Activated carbon capacity: Volume of carbon suited to the quantities of VOCs: it determines how often it must be replaced.
Monitoring: Clogging indicator, filter change signal, optional VOC sensor: carbon saturation cannot be seen. In France, recirculated air requires a device that signals any failure of the cleaning system (Art. R4222-16).
Interlock: Start and stop controlled by the printer, run-on delay after printing ends.
Noise and footprint: A noisy fume extractor ends up being unplugged: check the noise level for installation in an office or classroom.

11Frequently asked questions

Your questions answered

Is PLA safe?

PLA is one of the lowest-emitting filaments, but it still emits ultrafine particles and VOCs, including lactide. Colourants and additives alter these emissions. A PLA printer running for long periods in a small room also warrants a closed enclosure and filtered extraction.

Is an air purifier enough?

A free-standing purifier in the room treats the air once the pollutants have dispersed: the person working near the printer remains exposed to the plume. It can supplement capture at source on the printer enclosure, but never replace it.

My printer has a built-in filter: is that enough?

Built-in printer filters vary widely: some trap only a proportion of particles and contain little or no activated carbon. Check the efficiency of the HEPA filter, the quantity of activated carbon and the airtightness of the enclosure. For intensive or professional use, a dedicated fume extractor is safer.

Should the air be exhausted outside?

In France, INRS favours capture with exhaust to the outside after filtration, and recirculation of air from premises with specific pollution is permitted only if the air is effectively cleaned, with a device that signals any failures. For filament or resin printers, an enclosure connected to a HEPA and activated carbon fume extractor is recommended by CNRS, the FOPH and EPFL, provided the filters are replaced in time. For metal powders (nickel, cobalt), exhaust to the outside is essential: Ineris advises against discharging filtered air into work premises.

How often should filters be changed?

The pre-filter should be replaced as soon as it is clogged, and the combined HEPA and activated carbon filter according to the unit's indicator, and at least once a year for the 3D PrintPRO range. The clogging indicator light does not detect carbon saturation: an odour at the extractor outlet indicates that it needs changing, unless the unit is fitted with a VOC sensor.

Does an FFP2 mask protect you?

A well-fitted FFP2 or FFP3 mask traps particles, not gases: it does not protect against VOCs. Respiratory protection is reserved for occasional tasks (depowdering, filter changes) and does not replace capture at source.

Printing in a classroom: what precautions?

Pupils are more vulnerable and the teacher is exposed all day. Choose PLA or PETG, an enclosed printer, certified low-emission if possible (UL 2904 standard), connected to a filtering fume extractor, and a ventilated room; avoid running prints without extraction during lessons. Liquid resins should not be used with pupils.

Are resin printers more dangerous than filament printers?

The risks are different: resin mainly emits VOCs and exposes the skin to highly allergenic substances, while filament emits more ultrafine particles. In both cases: closed enclosure, filtered extraction with activated carbon and, for resin, nitrile gloves and safety glasses.

12References

Sources and studies cited

Links accessed in November 2026. Scientific studies are cited in their language of publication.

1
Ricaud M., Patrascu C., Malard S., Keller F.X. (INRS) (2021). Fabrication additive ou impression 3D. Références en santé au travail no. 165, TP 47.
France
2
Keller F.X., Ricaud M., Patrascu C. (INRS) (2020). Fabrication additive ou impression 3D utilisant des matières plastiques. Practical safety sheet ED 148.
France
3
Patrascu C. (INRS), with Sallé B. (INRS) and Grange B. (Carsat Rhône-Alpes) (2019). Fabrication additive ou impression 3D utilisant les poudres métalliques. Practical safety sheet ED 144.
France
4
INRS (2022). Fabrication additive : ce qu'il faut retenir, effets sur la santé, prévention. Web dossier.
France
5
Keller F.-X. (INRS) (2021). La fabrication additive : quelle prévention en entreprise ?. Hygiène & sécurité du travail no. 262, DC 29.
France
6
Patrascu C., Bau S., Clerc F. (INRS); Philippot C., Steck J., Artous S. (CEA) (2021). Expositions professionnelles lors de la fabrication additive utilisant des poudres métalliques. Hygiène & sécurité du travail no. 263, NT 90.
France
7
Keller F.-X. (INRS) (2023). Fabrication additive : état des lieux de la prévention et perspectives. Hygiène & sécurité du travail no. 270, CC 39 (INRS technical day, 17 May 2022).
France
8
Keller F.X., Robert L., Klingler J. (INRS) (2026). Characterization of emissions generated during additive manufacturing of polymer parts by the fused deposition modeling technique. Journal of Occupational and Environmental Hygiene 23(1), 8-17.
France
9
Bau S., Rousset D., Payet R., Keller F.X. (INRS) (2020). Characterizing particle emissions from a direct energy deposition additive manufacturing process and associated occupational exposure to airborne particles. Journal of Occupational and Environmental Hygiene 17(2-3), 59-72.
France
10
Azzougagh M.N., Keller F.X., Cabrol E., Cici M., Pourchez J. (Mines Saint-Étienne, INRS) (2021). Occupational exposure during metal additive manufacturing: a case study of laser powder bed fusion of aluminum alloy. Journal of Occupational and Environmental Hygiene 18(6), 223-236.
France
11
Dieu S., Darut G., Meunier L. et al. (Ineris) (2023). Synthèse du projet CaRPE (fabrication additive métallique). Ineris, project funded by ADEME.
France
12
Fenech G., Fenech A., Bensefa-Colas L., Crépy M.N. (AP-HP) (2024). Three-dimensional printing: a new source of exposure to (meth)acrylates in a dental technician. Contact Dermatitis 90(5), 534-536.
France
13
CNRS, Chemical Risk Prevention unit (2018). Impression 3D et risques chimiques. Prevention sheet.
France
14
Brasseur G., Delaval K. (INRS) (2021). Dossier « La plasturgie » (impression 3D : les bons réflexes). Travail & Sécurité no. 823.
France
15
Samba H., Demange V. (INRS) (2026). Exposition des travailleurs aux particules ultrafines métalliques en fabrication additive et effets respiratoires et cardiovasculaires (étude en cours). INRS, study ET2023-001.
France
16
INRS (2026). Valeurs limites d'exposition professionnelle aux agents chimiques en France (liste du 9 octobre 2026). VLEP database, companion document.
France
17
French Labour Code (2021). Article R4222-10 : concentrations moyennes en poussières dans les locaux à pollution spécifique (décret n° 2021-1763). Légifrance.
France
18
Steinle P. (Suva) (2016). Characterization of emissions from a desktop 3D printer and indoor air measurements in office settings. Journal of Occupational and Environmental Hygiene 13(2), 121-132.
Switzerland
19
FOPH, Federal Office of Public Health (2026). Imprimantes et photocopieurs : informations supplémentaires sur l'impression 3D. Information page.
Switzerland
20
EPFL, Occupational Health and Safety (2024). 3D Printers Guidelines (version 3). Internal directive.
Switzerland
21
Suva (2026). Valeurs limites d'exposition aux postes de travail. Suva 1903, April 2026 edition, and online VME database.
Switzerland
22
EU-OSHA (Junte J.) (2017). 3D printing and additive manufacturing – The implications for OSH. European Agency for Safety and Health at Work, discussion paper.
European Union
23
Beisser R., Buxtrup M., Fendler D. et al. (IFA, DGUV) (2017). Inhalative Exposition gegenüber Metallen bei additiven Verfahren (3D-Druck). Gefahrstoffe – Reinhaltung der Luft 77(11/12), 487-496.
Germany
24
Beisser R., Werner S., Heinrich B., Pelzer J. (IFA, DGUV) (2020). Emissionen aus 3D-Tischdruckern – Nachstellende Untersuchungen – Teil 1. Gefahrstoffe – Reinhaltung der Luft 80(1-2), 53-60.
Germany
25
Gümperlein I., Fischer E., Dietrich-Gümperlein G. et al. (LMU Munich) (2018). Acute health effects of desktop 3D printing (fused deposition modeling) using acrylonitrile butadiene styrene and polylactic acid materials: an experimental exposure study in human volunteers. Indoor Air 28(4), 611-623.
Germany
26
BfR, German Federal Institute for Risk Assessment (2020). 3D-Druck – eine „staubige“ Angelegenheit?. Communication no. 050/2020.
Germany
27
Seeger S., Rasch F., Erdmann K., Brödner D., Wilke O. (BAM, for UBA) (2020). Weiterentwicklung des Prüfwertes für Ultrafeinstaubpartikel beim Umweltzeichen Blauer Engel für Drucker. Umweltbundesamt, TEXTE 217/2020.
Germany
28
Miljøstyrelsen, Danish Environmental Protection Agency (Jacobsen E., Larsen P.B. et al.) (2017). Risikovurdering af 3D-printere og 3D-printede produkter. Kortlægning af kemiske stoffer i forbrugerprodukter no. 160.
Denmark
29
Jensen A.C.Ø., Harboe H., Brostrøm A., Jensen K.A., Fonseca A.S. (NRCWE) (2020). Nanoparticle exposure and workplace measurements during processes related to 3D printing of a metal object. Frontiers in Public Health 8, 608718.
Denmark
30
Väisänen A.J.K., Hyttinen M., Ylönen S., Alonen L. (2019). Occupational exposure to gaseous and particulate contaminants originating from additive manufacturing of liquid, powdered, and filament plastic materials and related post-processes. Journal of Occupational and Environmental Hygiene 16(3), 258-271.
Finland
31
Väisänen A., Alonen L., Ylönen S., Hyttinen M. (2022). Organic compound and particle emissions of additive manufacturing with photopolymer resins and chemical outgassing of manufactured resin products. Journal of Toxicology and Environmental Health, Part A 85(5), 198-216.
Finland
32
Viitanen A.-K., Kallonen K., Kukko K. et al. (FIOH) (2021). Technical control of nanoparticle emissions from desktop 3D printing. Indoor Air 31(4), 1061-1071.
Finland
33
Kangas A., Kukko K., Kanerva T. et al. (FIOH, Aalto) (2023). Workplace exposure measurements of emission from industrial 3D printing. Annals of Work Exposures and Health 67(5), 596-608.
Finland
34
TTL, Finnish Institute of Occupational Health (2025). Exposure control in metal 3D printing work. Exposure control sheet.
Finland
35
Ljunggren S.A., Karlsson H., Ståhlbom B. et al. (2019). Biomonitoring of metal exposure during additive manufacturing (3D printing). Safety and Health at Work 10(4), 518-526.
Sweden, Norway
36
Assenhöj M., Almstrand A.-C., Kokelj S. et al. (2023). Occupational exposure and health surveys at metal additive manufacturing facilities. Frontiers in Public Health 11, 1292420.
Sweden
37
HSE (Hall S., Evans G.) (2023). Exposure to metal powders in additive manufacturing. Health and Safety Executive, Research Report RR1195.
United Kingdom
38
Stabile L., Scungio M., Buonanno G., Arpino F., Ficco G. (2017). Airborne particle emission of a commercial 3D printer: the effect of filament material and printing temperature. Indoor Air 27(2), 398-408.
Italy
39
Creytens K., Gilissen L., Huygens S., Goossens A. (2017). A new application for epoxy resins resulting in occupational allergic contact dermatitis: the three-dimensional printing industry. Contact Dermatitis 77(5), 349-351.
Belgium
40
Wojtyła S., Klama P., Baran T. (2017). Is 3D printing safe? Analysis of the thermal treatment of thermoplastics: ABS, PLA, PET, and nylon. Journal of Occupational and Environmental Hygiene 14(6), D80-D85.
Poland
41
Miller M.R., Raftis J.B., Langrish J.P. et al. (2017). Inhaled nanoparticles accumulate at sites of vascular disease. ACS Nano 11(5), 4542-4552.
United Kingdom, Netherlands
42
Stephens B., Azimi P., El Orch Z., Ramos T. (2013). Ultrafine particle emissions from desktop 3D printers. Atmospheric Environment 79, 334-339.
United States
43
Azimi P., Zhao D., Pouzet C., Crain N.E., Stephens B. (2016). Emissions of ultrafine particles and volatile organic compounds from commercially available desktop three-dimensional printers with multiple filaments. Environmental Science & Technology 50(3), 1260-1268.
United States
44
Zhang Q., Wong J.P.S., Davis A.Y., Black M.S., Weber R.J. (2017). Characterization of particle emissions from consumer fused deposition modeling 3D printers. Aerosol Science and Technology 51(11), 1275-1286.
United States
45
Stefaniak A.B., LeBouf R.F., Yi J. et al. (NIOSH) (2017). Characterization of chemical contaminants generated by a desktop fused deposition modeling 3-dimensional printer. Journal of Occupational and Environmental Hygiene 14(7), 540-550.
United States
46
House R., Rajaram N., Tarlo S.M. (2017). Case report of asthma associated with 3D printing. Occupational Medicine 67(8), 652-654.
Canada
47
Chan F.L., House R., Kudla I., Lipszyc J.C., Rajaram N., Tarlo S.M. (2018). Health survey of employees regularly using 3D printers. Occupational Medicine 68(3), 211-214.
Canada
48
Davis A.Y., Zhang Q., Wong J.P.S., Weber R.J., Black M.S. (2019). Characterization of volatile organic compound emissions from consumer level material extrusion 3D printers. Building and Environment 160, 106209.
United States
49
Zhang Q., Pardo M., Rudich Y. et al. (2019). Chemical composition and toxicity of particles emitted from a consumer-level 3D printer using various materials. Environmental Science & Technology 53(20), 12054-12061.
United States, Israel
50
Stefaniak A.B., Johnson A.R., du Preez S. et al. (NIOSH) (2019). Evaluation of emissions and exposures at workplaces using desktop 3-dimensional printers. Journal of Chemical Health & Safety 26, 19-30.
United States
51
Farcas M.T., Stefaniak A.B. et al. (NIOSH) (2019). Acrylonitrile butadiene styrene (ABS) and polycarbonate (PC) filament three-dimensional (3-D) printer emissions-induced cell toxicity. Toxicology Letters 317, 1-12.
United States
52
IARC (2019). Styrene, styrene-7,8-oxide, and quinoline. IARC Monographs on the Identification of Carcinogenic Hazards to Humans, vol. 121.
International
53
IARC (2025). Talc and acrylonitrile. IARC Monographs, vol. 136 (June 2024 evaluation).
International
54
ISO / ASTM (2023). NF EN ISO/ASTM 52931 – Additive manufacturing of metals – Environment, health and safety – General principles for use of metallic materials. International standard.
International
55
ISO (2024). ISO 27548 – Additive manufacturing of plastics – Environment, health, and safety – Test method for determination of particle and chemical emission rates from desktop material extrusion 3D printer. International standard.
International
56
Donaldson BOFA (2026). Fiches techniques 3D PrintPRO 2, 3D PrintPRO 3 et 3D PrintPRO 4. Manufacturer documentation.
United Kingdom

This guide is an information summary written by AirPropre on the basis of publicly available publications. It does not replace the employer's risk assessment, nor the advice of your occupational health and prevention service, your regional health insurance fund (Carsat, Cramif, CGSS) or Suva.

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3D printing fumes: beware of invisible emissions

Four key messages

How a 3D printer pollutes the air

Each process has its own emissions

Filament deposition

Photopolymer resin

Material jetting

Polymer powder

Metal powder

What each material releases

Where particles go, and what they cause

What the studies say

FRFrance

CHSwitzerland

UEEurope

INTKey international studies

What the law requires of employers

Prevention: in what order to act

Effective filtration: three complementary stages

The 3D PrintPRO range, designed for 3D printing

3D PrintPRO 2

3D PrintPRO 3

3D PrintPRO 4

Your situation in four questions

Your questions answered

Sources and studies cited

Have your 3D printing emissions assessed