Manufacturer: KOKEN LTD.
Model: 1005 Series

Important points when wearing a mask

Dust masks utilize high-efficiency filters to effectively prevent the inhalation of hazardous particles. To protect yourself from inhaling dust while wearing a dust mask, both the performance of the filter and the “tight seal” (fit) between the mask and your face are critical.

1. Filter Technology with High Particle Collection Efficiency

Mighty (Uni) Micron Filter
Using unique technology, wool fibers are electrostatically charged, allowing electrostatic force to draw particles to the fiber surface. This is the primary mechanism for capturing particles. A high-density fiber structure is unnecessary, successfully integrating the two contrasting features: “high collection efficiency” and “low inhalation resistance.” It consistently maintains the highest standard of performance and quality, making it an excellent long-term filter solution.

Applied products are on P.4 ~ 6, P.11

Alpha Ring Filter

Increasing the fiber density of the filter enhances collection efficiency. To meet airflow resistance standards, paper filters traditionally require an expanded surface area.

For the first time in Japan, ultra-fine fibers were formed into pristine circular shapes in a single process, creating the Alpha Ring filter. Today, this filter continues to succeed in expanding the surface area while maintaining a compact shape, significantly reducing airflow resistance.

Applied products are from page P.8 to P.11

Dust Respirator Standards

In addition to JIS standards, dust respirators are tested according to assay standards based on national regulations. These standards are comprehensive, ensuring that products meeting strict safety requirements are manufactured.

Note: The table below is excerpted from the “Dust Respirator Standards”.

( ) indicates products without an exhalation valve.

High Efficiency Filter + Ergonomic Face Seal

2. Facepiece Fit Technology

Even if a dust mask has a high collection efficiency filter, it is ineffective if dust leaks through the facepiece seal during use. The primary cause of exposure is the “gap at the facial contact area.” We consider mask fit to be just as important as filter performance. Therefore, our company developed technology to enhance the airtightness of the facial contact area early on.

Silicone Facepiece
Silicone is a hypoallergenic material that is gentle on the skin. Its surface is flexible and effortlessly adapts to facial movements, ensuring a comfortable fit and stability during use.

HAWC harness strap
The strap design ensures a high level of fit, maximizing the “suction” effect when wearing the mask to ensure an airtight seal on the face.

Freeposition Underchin
The unique curve of the facial contact area prevents dust entry. The nose section is aligned first, allowing it to accommodate various facial dimensions and providing a secure fit for a wide range of face sizes (see image below).

Fit Status of the Freeposition Underchin Facepiece
(Cross-sectional simulation to show the contact position between the mask and the chin).

For large faces: Uses the outer section of the mask to adjust the fit around the chin.

For small faces: Uses the inner section of the mask to adjust the fit around the chin.

FF Lip		Wearing Stability		Internal Fit Checker
	Designed for various face shapes; the cushion naturally fits your face.		Utilizes a 3D poly-band harness that matches head shapes to enhance fit and seal.		Fit checker is integrated inside, helping to check the mask seal at any time (available for models 1005, 1010A, 1015, 1180 series).

Replaceable Dust Mask
Mighty Micron Filter

The yellow filter is the hallmark
Mighty Micron Filter

Thanks to proprietary technology, this filter is created by electrostatically charging the base wool fiber material. In addition to a strong electrostatic force, a 3-layer structure with a void space between two collection layers achieves low fiber density while combining two opposing characteristics: high collection efficiency and low inhalation resistance.

• Fit checker: Perform a seal test (fit test) simply by operating a lever.
• Under-chin: Unique curve design enhances the seal at the facial contact area.
• Silicone: Uses soft, skin-friendly silicone for a comfortable wearing experience.
• Size S available: Small face size options are available for these models.
• Micron: Employs high-performance electrostatic filters compliant with RL classifications.

Sakai – Model 1005R-08

Integrated Fit Checker – Suitable for welding operations

Model Assay Certificate: TM540
Assigned Protection Factor: 10
Classification: RL2

• Fit Checker (Integrated seal check lever)
• Under-chin support
• Silicone seal
• Size S available
• Micron Filter

Sakai – Model 1005RR-05

Compatible with KBC filter for ozone and organic odor removal
Integrated Fit Checker

Model Assay Certificate: TM541
Assigned Protection Factor: 10

Compatible with KBC filter
Classification: RL2

• Fit Checker
• Under-chin support
• Silicone seal
• Size S available
• Micron Filter

Sakai – Model 1005R-AL-02

Suitable for environments with radiant heat
Aluminized coating
Integrated Fit Checker

Model Assay Certificate: TM543
Assigned Protection Factor: 10

Classification: RL2

• Fit Checker
• Under-chin support
• Silicone seal
• Size S available
• Micron Filter

Sakai – Model 1005RRX-05

Compatible with KBC filter for ozone and organic odor removal
Integrated Fit Checker
4-point head harness

Model Assay Certificate: TM542
Assigned Protection Factor: 10

Compatible with KBC filter
Classification: RL2

• Fit Checker
• Under-chin support
• Silicone seal
• Size S available
• Micron Filter

▲ Shared Replacement Parts for 1005 Series

• Inhalation Valve (Circular)
• Exhalation Valve (T-6K)
• Moisture Sponge (Egg-shaped)

Replacement Filters · Optional Accessories

Mighty Micron Filter for 1005-02	KBC Filter for 1005 (Ozone & organic odor removal, 5 sets/pack) (Optional) → For 1005RR / 1005RRX

（Head Harness Types）
Please replace the head straps periodically.

Collection Efficiency with DOP Particles (using 1005R)

Up to a load of 200 mg of DOP particles, the minimum collection efficiency was 98.74%. Even for DOP particles—which tend to degrade electrostatic forces faster than other oil mists—the Mighty Micron filter maintains very high performance.

Collection Efficiency against Welding Fume (30 mg/m³) – using 1005R

During the accumulation of 100 mg of welding fume, the minimum collection efficiency was 99.927%. After this, the mechanical sieving effect becomes dominant, maintaining extremely high efficiency. → Efficiency at 100 mg load: 99.993%.

Built-in Fit Checker – Rapid Seal Verification

Regardless of filter efficiency, a mask provides no protection if not worn correctly. For this reason, national regulations require replaceable dust masks to have an easy method for fit testing.
Our company was the first in Japan to develop an integrated fit checker, allowing for simpler seal checks. There is no need for external testing equipment; users can verify the fit instantly on-site.
This design encourages workers to perform seal checks every time they don the mask, ensuring consistent safety.

Applicable Series:
1005 series, 1010A, 1015, 1180 series

Simply move the lever to close the inhalation port and perform a negative pressure seal check.

Sakai Model 1010A-06

RL1 Rating
Integrated Fit Checker
Lightest in class: 76 g (compared to other replaceable filter models from Koken)

Model Assay Certificate: TM560
Assigned Protection Factor: 4

• Fit Checker
• Mighty Micron Filter

Replacement Parts

• Inhalation Valve – Oval type (Small)
• Exhalation Valve – T-6K type
• Moisture Sponge – Egg-shaped

Sakai Model 1015-02

RL2 Rating
Integrated Fit Checker
Silicone Facepiece

Model Assay Certificate: TM570
Assigned Protection Factor: 10

• Fit Checker
• Freeposition Underchin design
• Silicone seal
• Mighty Micron Filter

Replacement Parts

• Inhalation Valve (Oval small type)
• Exhalation Valve (T-6K type)
• Moisture Sponge (Egg-shaped)