Focus | BLS Flat series: the flat-design filter facepiece series
BLS Zer0 Flat and BLS 600next series filter facepieces feature a flat design that ensures a good balance between protection and ease of breathing.
In recent years, the market for respiratory protection devices has seen a rise in the adoption of flat-design filtering facepieces.
This configuration, often consisting of three flaps, allows for better adaptability to the face, greater breathing comfort and greater compatibility with other PPE.
In this article, we focus on two BLS series that feature this characteristic: BLS Zer0 Flat and BLS 600next, analysing them in detail, highlighting similarities and differences, and offering useful insights for professional users and purchasing managers.

What are the main advantages of flat design?
The flat, three-panel design allows the facepiece to follow the natural movements of the face during breathing, facial expressions or lateral movements, maintaining a constant seal and protection. An innovative feature of the BLS design is the folded bottom flap: when opened to put on or take off the facepiece, the risk of contaminating the inside of the facepiece is minimised, which is an important advantage in critical environments.
In addition, this geometry can contribute to an 'optimal' internal volume: neither too small (which would impair breathing) nor too large (which would compromise comfort and compatibility). A well-calibrated design offers a balance between protection and ease of breathing.
BLS Zer0 Flat: key features
BLS Zer0 Flat series is one of the best solutions in respiratory protection in terms of breathing comfort, guaranteeing P3 protection with the breathability of a P1.
The devices in this series feature a surface micro-mesh that prevents clogging of the filter material and absorption of liquids, extending the life of the device. In addition, the design allows them to be folded and stored when not in use and has the advantage of not having metal points that can be uncomfortable when in contact with the face and the elastic bands are made of textile material for greater acceptability by operators.
Another strength of BLS Zer0 33 is undoubtedly its high breathability. This translates into less moisture build-up inside the facepiece, reducing fatigue during prolonged use and significantly improving comfort without compromising the level of protection. The efficiency of the design and the choice of materials ensure optimal water vapour transmission, allowing the skin to breathe and keeping the face dry.

BLS Zer0 Flat series offers the following models:
- BLS Zer0 33: With Eolo® valve, welded elastic bands and partial internal seal. Available in two sizes: S and M/L.
- BLS Zer0 33 NV: Without exhalation valve, with welded elastic bands and partial internal seal. Available in two sizes: S and M/L.
The availability of two sizes meets the needs for fit and seal of the facepiece on a variety of face shapes and therefore allows for an excellent success rate in fit testing. This requirement is even more important given that this is a filtering facepiece used in contexts that require P3 protection.
BLS 600next: key features
BLS 600next series represents BLS's offering in the FFP2 segment with a three-flap design, in an updated version geared towards everyday use in moderate-risk environments.
The filtering facepieces in this series can be used to protect the wearer's respiratory tract from solid and/or non-volatile liquid particles up to 12 times the weighted limit value (TLV-TWA). The four-point elastic harness, internal nose clip and sealing gasket ensure excellent adaptability for most face shapes. In addition, the availability of two sizes has been designed to achieve the best fit test results, even for small faces.
This model is therefore a suitable solution for contexts where FFP2 protection is adequate, prioritising comfort, ease of use and versatility.

This series is available with or without an exhalation valve and in two sizes.
- BLS 670next: two sizes, S and M/L, without exhalation valve, class FFP2 NR D
- BLS 680next: two sizes, S and M/L, with exhalation valve, class FFP2 NR D
Comparison between BLS Zer0 Flat and BLS 600next
Feature | BLS Zer0 Flat | BLS 600next |
---|
Maximum protection class | FFP3 | FFP2 |
Flat three-panel design | ✔ | ✔ |
Single pack | ✔ | ✔ |
Internal nose clip | ✔ | ✔ |
Elastic bands with no exposed metal | ✔ - fabric | ✔ - rubber |
Armor protective layer | ✔ | |
Valve | High-performance Eolo® (versions available with/without valve) | Standard (versions available with/without valve) |
Comfort | Very high, thanks to high breathability and use of advanced technologies | Excellent for FFP2 class; valve helps in harsh conditions |
Field of vision / glasses compatibility | Wide field of vision guaranteed | Similar, optimised design |
Available sizes | S and M/L | S and M/L |
Storage life | 10 years | 10 years |
Recommended areas of use | Where high protection is required (e.g. environments with toxic dust, fumes and aerosols, as well as nanoparticles) | Moderate risk environments, healthcare, light industry, everyday contexts |
In summary: flat three-panel filter facepieces are currently one of the most interesting developments in respiratory protection, as they combine a secure fit, comfort and ease of use. BLS, with its Zer0 Flat and 600next lines, offers two well-designed solutions for different needs: BLS Zer0 Flat is the preferred choice when protection is an essential requirement (FFP3), while BLS 600next is a valid solution that offers an ideal balance between protection (FFP2), comfort and versatility.
Visit the BLS Zer0 Flat and BLS 600next product pages to download the technical data sheets and find all the details you need.