KOKEN LTD.
Koken 1180 Series Dust Mask

Manufacturer: KOKEN LTD.
Model: 1180 Series
Important points when wearing a mask
Dust masks utilize high-efficiency filters to effectively prevent the inhalation of hazardous particles. To protect yourself 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.
| 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”.
| Replaceable Dust Respirator | Isolation Type Dust Respirator |
|---|---|
| Direct-Connection Type Dust Respirator | |
| Disposable Dust Respirator | |
| Test Particles | Type | NaCl (Sodium Chloride) | DOP (Dioctyl Phthalate) | ||
|---|---|---|---|---|---|
| Particle Size | 0.06 μm to 0.1 μm | 0.15 μm to 0.25 μm | |||
| Concentration | 50mg/m³ or less | 100mg/m³ or less | |||
| Test Flow Rate | 85 ℓ/min | 85 ℓ/min | |||
| Particle Collection Efficiency (Continuous measurement; must meet values in the right column) | For NaCl particles Load up to 100mg | For DOP particles Load up to 200mg | |||
| Replaceable Type | RS1 | 80.0% or higher | RL1 | 80.0% or higher | |
| RS2 | 95.0% or higher | RL2 | 95.0% or higher | ||
| RS3 | 99.9% or higher | RL3 | 99.9% or higher | ||
| Disposable Type | DS1 | 80.0% or higher | DL1 | 80.0% or higher | |
| DS2 | 95.0% or higher | DL2 | 95.0% or higher | ||
| DS3 | 99.9% or higher | DL3 | 99.9% or higher | ||
| Inhalation Resistance (Test Flow Rate 40 ℓ/min) | Replaceable Type | Disposable Type | |||
| RS1 RL1 | 70Pa or less | DS1 DL1 | 60Pa or less (45Pa or less) | ||
| RS2 RL2 | 80Pa or less | DS2 DL2 | 70Pa or less (50Pa or less) | ||
| RS3 RL3 | 160Pa or less | DS3 DL3 | 150Pa or less (100Pa or less) | ||
| Exhalation Resistance (Test Flow Rate 40 ℓ/min) | Replaceable Type | Disposable Type | |||
| RS1 RL1 | 70Pa or less | DS1 DL1 | 60Pa or less (45Pa or less) | ||
| RS2 RL2 | 70Pa or less | DS2 DL2 | 70Pa or less (50Pa or less) | ||
| RS3 RL3 | 80Pa or less | DS3 DL3 | 80Pa or less (100Pa or less) | ||
Values in ( ) are for products without an exhalation valve.
| Exhalation Valve Airtightness | Exhalation valve leak test | – Internal pressure must drop immediately during suction. – Time for internal pressure to return to normal must be 15 seconds or more. |
|---|---|---|
| CO2 Concentration Increase | Measured using a test headform and artificial lung. The difference in CO2 concentration in inhaled air with and without the mask must be 1.0% or less. | |
| Dead Space | Value calculated from the CO2 Concentration Increase Test. | |
| Inhalation Resistance Increase | Test Particles | NaCl (Sodium Chloride) |
|---|---|---|
| Test Flow Rate | After dust accumulation at 85 ℓ/min, measurement is taken at 40 ℓ/min. | |
| Dust Accumulation Amount | 100mg |
Test Particles & Efficiency Disposable / Replaceable | S | L | Classification (Efficiency) | |
|---|---|---|---|---|
| Test particle: Solid NaCl | Test particle: Liquid DOP | |||
| R | Replaceable Dust Respirator | RS1 | RL1 | Class 1 (≥ 80.0%) |
| RS2 | RL2 | Class 2 (≥ 95.0%) | ||
| RS3 | RL3 | Class 3 (≥ 99.9%) | ||
| D | Disposable Dust Respirator | DS1 | DL1 | Class 1 (≥ 80.0%) |
| DS2 | DL2 | Class 2 (≥ 95.0%) | ||
| DS3 | DL3 | Class 3 (≥ 99.9%) | ||
High Efficiency Filter + Face-Friendly Surface
2. Surface Engineering for a Better Facial Fit
Even if a dust mask has a high collection efficiency filter, it is useless if dust leaks in through the facepiece seal. The primary cause of leakage is the “gap at the contact area when wearing the mask.” We consider the fit of the mask to be as important as the filter performance. Therefore, our company has developed technology to enhance the airtightness of the facial contact area.

Silicone Facepiece
Silicone is a hypoallergenic material that is gentle on the skin. Its surface is flexible and easily adapts to body movements, ensuring wearing comfort and stability during use.
HAWC Harness
The harness design ensures high tension and maximizes the “suction” effect when wearing the mask, guaranteeing an airtight seal on the face.
Freeposition Under-Chin
The special shape of the facial contact area prevents dust entry. The nose section is adjustable for different sizes, ensuring a perfect fit for a wide range of facial dimensions (see image below).

Fit Status of the Freeposition Under-Chin 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 Safety | 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 the feeling of fit and seal. | ![]() | Built-in fit checker allows for seal checks at any time (for models 1005, 1010A, 1015, 1180 series). |
Harness Types
Please replace the harness regularly.

Sakaki – Model 1180-05
Double-layer bonnet structure protecting the exhalation valve.
RL2 Classification
Built-in Fit Checker
Compact, lightweight model – 99 g
Size S available
Model Assay Certificate: TM538
Assigned Protection Factor: 10
Can be used as a gas mask (G-7 configuration)
(Absorbent canisters sold separately)
Gas Mask Certificate: TN382

Option: Moisture Sponge Type A
- Fit Checker (rapid seal test)
- Under-Chin cushion
- Silicone facepiece
- Size S available
| Particle Collection Efficiency | 95.0% or higher (Average 98.0%) |
|---|---|
| Inhalation Resistance | 80Pa or less (Average 72Pa) |
| Exhalation Resistance | 45Pa or less (Average 25Pa) |
| Inhalation Resistance Increase | ― (Average 123Pa) |
| Weight | 114g or less (Average 99g) |
| Harness | RB Type |
Consumable Parts:
- Inhalation valve: Small 03 type
- Exhalation valve: T-7 type
Sakaki – Model 1180C-05
Equipped with Activated Carbon Filter
RL2 Classification
Suitable for organic odors and ozone below permissible levels
Built-in Fit Checker
Warning: Not a dedicated gas mask for high concentrations.
Model Assay Certificate: TM539
Assigned Protection Factor: 10

Option: Moisture Sponge Type A
- Fit Checker (rapid seal test)
- Under-Chin cushion
- Silicone facepiece
- Size S available
- Low inhalation resistance
- Activated carbon filter
| Particle Collection Efficiency | 95.0% or higher (Average 98.8%) |
|---|---|
| Inhalation Resistance | 80Pa or less (Average 71Pa) |
| Exhalation Resistance | 45Pa or less (Average 27Pa) |
| Inhalation Resistance Increase | ― (Average 133Pa) |
| Weight | 113g or less (Average 98g) |
| Harness | RB Type |
Consumable Parts:
- Inhalation valve: Small 03 type
- Exhalation valve: T-7 type
▲ Shared Replacement Parts for 6 Models (1181R-03, 1121R-08, 1191SD-03, etc.)
- Inhalation valve: circular type
- Moisture sponge: oval type
Replacement Filters · Optional Accessories
| LAS-52 (for 1181R) | LAS-52C (for 1181RC) | LAS-1 (for 1121R, 1121RX, 1191SD, 1191D) | LAS-51 (for 1180) | LAS-51C (for 1180C) | KBC Filter for 1121 / 1191 (Ozone & organic odor removal – pack of 5) For: 1121R / 1121RX / 1191SD / 1191D / 1122R (Optional) | Fit Test Device – Type F For: 1181R, 1181RC, 1121R, 1121RX, 1191SD, 1191D (Optional) |
![]() | ![]() | ![]() | ![]() | ![]() | ![]() | ![]() |
| Screw-in – Pack of 2 | Screw-in – Pack of 2 | Pack of 2 | Screw-in – Pack of 2 | Screw-in – Pack of 2 |
- Under Chin: Specialized curve enhances seal at facial contact points.
- Silicone: Soft, skin-friendly material provides a comfortable wearing feel. Facepiece seal uses silicone.
- Size S Available: Small size option for users with petite faces.
- Low Resistance: Uses Alpha Ring filter for low breathing resistance, allowing for long-duration work.
- Speaking Diaphragm: Allows communication and instructions to be heard without removing the mask.
- Activated Carbon: Effectively removes low-concentration ozone using carbon-treated filters.
- Micron: High-performance electrostatic filter compliant with RL classification.
- Fit Checker: Perform a manual seal test by simply operating the lever.
Double-Layer Bonnet Structure The exhalation valve is shielded inside the bonnet from external factors like wind. Exhaled air accumulated in the upper bonnet acts as a buffer (barrier), preventing direct external impact and protecting the valve. This significantly improves exhalation valve performance and stability under real usage conditions. | ![]() |
| Note on Replacement Always replace filters and consumable parts according to recommended schedules. |




























