What is the difference between 3Ply Face Masks – ASTM Levels 1, 2 and 3?

What is the difference between 3Ply Face Masks – ASTM Levels 1, 2 and 3?

Choosing the right type of face mask has never been more crucial than now, and although large quantities of quality face masks may be hard to source, it’s important not to simply select the cheapest, or those available in the largest quantities. Take your time to find one that is the right grade for your application, to ensure you get the safest and most relevant protection possible.

The “4 Fs” of selecting the right mask

For both safety and comfort, follow these four best practices for mask selection:

  • Filtration- When smoke is present or interacting with a patient with a known or suspected aerosol transmittable disease, use a high filtration mask (N95 respirator).
  • Fluid resistance- Wear a fluid resistant mask if there’s any chance of blood and/or bodily fluid splatter. ASTM Level 3 surgical masks are recommended for the OR.
  • Features- Depending on the setting, choose ear loops or ties to secure your mask (ear loops are not recommended for the OR). To reduce distractions from fogging issues, consider anti-fog film, foam and tapes. And to keep eyes clear of blood and splash, wear shields and protective eyewear.
  • Fit- Even the right mask incorrectly worn could put you at risk. Be sure to cover your nose and mouth completely, creating a seal around the face to prevent gaps that increase the risk of inhalation exposure.  A fifth best practice is feel, the right mask should also be comfortable and promote breathability.

Surgical face masks are generally graded through ASTM (American Society for Testing and Materials), which publishes the technical standards for products, materials, systems and the likes. There are currently around 12,000 ASTM standards in use worldwide.

Not all masks are graded so make sure you check that your product of choice has an ASTM grade or is from a reputable manufacturer. This will ensure you are comfortable that you have the appropriate level of protection, and thus minimizing the risk in your workspace, whether it be surgery, pathology, or research.

Ensure you find masks which have the ASTM level printed on the box, with the level of fluid resistance (see table below) shown. If this is not present, the masks are non-compliant with Australian standards and regulations.

Which mask is which?

As per the test results, masks are rated numerically, on the barrier performance of the material.

  • Level One: Low barrier protection. Only for general use, not used for aerosols, spray or fluids.
  • Level Two: Moderate barrier protection. Use for low to moderate levels of aerosols, spray and/or fluids.
  • Level Three: Maximum barrier protection. Use for high risk of fluid, spray and/or fluids.

Key Testing Metrics:

Masks are tested to five key performance criteria:

  • Bacterial Filtration Efficiency: measures and tests the bacteria filtered out by the mask (larger than three microns).
  • Particulate Filtration Efficiency: measures and tests the particles filtered out by the mask (larger than one micron).
  • Fluid Resistance: evaluates and tests the resistance of the face mask to the penetration of approximately 2 mL of synthetic blood at a high velocity. Based on visual evidence, the mask either passes or fails the test.
  • Breathability: tests the resistance of the face mask to a controlled airflow driven at the mask. Lower breathing resistance results indicates a higher level of comfort for the user.
  • Flammability: tests the time required for an exposed flame to proceed up the mask material at a distance of five inches. Normal flammability is known as Class One.

The more resistance the mask offers to any of these criteria, the higher the grade, and thus the higher the protection. Higher protection masks are more suited to surgery or working with chemicals, however, will not protect again vapors, which will need a respirator.

It is important to ensure you are thorough with your research to find the most appropriate PPE when procuring. Get in touch with our educated and unbiased staff at HILDR Group, or browse our product specifications for Level 1, 2 and 3 face masks.


Level One Mask

Level Two Mask

Level Three Mask

ASTM F1862 (Fluid Resistance)

80 mmHg

120 mmHg

160 mmHg

MIL-M-36954 C (Breathability)

<4 mm H20

<5 mm H20

<5 mm H20

ASTM F2101: Bacteria Filtration Efficiency (BFE) (Filtration 3μm)

≥ 95%

≥ 98%

 ≥ 98%

ATSM F2299: Particle Filtration Efficiency (PFE) (Filtration 1μm)

≥ 95% @ 0.1 micron

≥ 98% @ 0.1 micron

≥ 98% @ 0.1 micron

16 CFR Part 1610 (Flammability)

Class One

Class One

Class One


In conclusion, it is of also of note that even the ASTM-Rated face masks do not necessarily provide all the respiratory protection from airborne diseases. To further reduce the risk of breathing in airborne disease particles, a fit-tested respirator is required.