Particles Emission from an Industrial Spray Coating Process Using Nano-Materials | JoVE Visualize

Area of Science:

Occupational Health and Safety
Nanotechnology
Environmental Science

Background:

Industrial spray coating is widely used for large surfaces but can be a significant source of worker exposure to ultrafine particles (UFPs).
Characterizing nanoparticle release during these processes is crucial for assessing and mitigating potential health risks.
Titanium dioxide (TiO2-N) and silver (AgHEC) nanoparticles are commonly used in coatings.

Purpose of the Study:

To quantify and characterize the release of TiO2-N and AgHEC nanoparticles during industrial spray coating of PMMA and polyester.
To assess worker exposure levels to these nanoparticles at different locations within the spray chamber.
To compare nanoparticle release concentrations with established nano reference values (NRVs).

Main Methods:

A monitoring campaign was conducted at an industrial spray-coating facility.
On-line and off-line instruments were used to characterize aerosol particles inside the spray chamber at near field (NF) and far field (FF) locations.
Measurements focused on particle number and mass concentrations across various size ranges.

Main Results:

TiO2-N suspensions generated higher particle number concentrations (0.3-1 µm) than AgHEC suspensions (1.9x10^2 p/cm³ vs 2.5x10¹ p/cm³).
At worst-case scenarios for TiO2-N, spray spikes at FF correlated with NF, with a 1-minute time lag indicating a diffusion speed of 0.1 m/s.
Averaged mass concentration ratios of NF to the spray chamber were 1.7% for TiO2-N and 1.5% for AgHEC.
Particle number concentrations for TiO2-N (0.3-1 µm) were similar for PMMA and polyester substrates.
Aerosol number concentrations at NF for both suspensions were below NRVs (16x10³ p/cm⁻³).

Conclusions:

Industrial spray coating processes release UFPs, with TiO2-N suspensions showing higher emission rates than AgHEC.
Worker exposure to nanoparticles can be significant, particularly under high-flow conditions, necessitating exposure control measures.
While measured concentrations were below NRVs, continuous monitoring and risk assessment are vital for occupational safety in spray coating operations.