EN 12254 Screens for Laser Work Areas - Safety Requirements and Testing

The European standard "EN 12254 Screens for laser work areas - Safety requirements and tests" describes the functional requirements and product labeling requirements applicable to temporary and permanent passive screens (screens) for protection against laser radiation. This standard includes test methods for testing functional performance and specifications for user documentation to be provided with the product.

The screens are designed to protect the user from:

Unintentional exposure to direct or scattered laser radiation
Duration exposure to laser radiation based on functional requirements determined by risk assessment.

This standard applies to inspected displays for installations in workplaces where laser radiation with a maximum average power of 100 W or a single pulse energy of 30 J occurs in the spectral range between 180 nm (0,18 µm) and ^{10⁶ nm (1000 µm).}

This standard applies only to protection against laser radiation. It does not apply to other hazards, including hazards from secondary radiation that may arise, for example, during material processing.

This standard provides guidance on how to select such displays. Laser enclosures and housings (EN 60825-1) supplied as part of a laser product or for installation in a laser system to form a laser product are not considered within the scope of this standard.

For the purposes of this standard, the terms and definitions given in EN 165, EN 60825-1, EN 60825-4 and IEC 60050-845 standards are valid.

The requirements in this standard are specified as follows:

Spectral transmittance: The relationship between spectral transmittance at the laser wavelength and resistance to laser radiation is based on the maximum permissible exposure specified in EN 60825-1. To facilitate product specification, tests were performed for the laser test conditions described in the table titled "Test period applicable to screens for laser work areas." The table gives the test condition (corresponding laser designation) based on:
- D (continuous wave laser)
- I (pulsed laser)
- R (Giant pulsed laser)
- M (Mode-coupled pulsed laser)

The pulse durations listed are typical values for lasers. A laser with a pulse length in this range is recommended for testing. The total exposure time for each test should be approximately 100 seconds.

Resistance to laser radiation: Screens must not lose their protective properties under the influence of laser radiation with power and energy density specified in the table entitled “Scale numbers of screens for laser working areas (maximum spectral transmittance and resistance to laser radiation)” and must remain within the scale number, including induced transmittance (reversible whitening).
Stability to UV radiation: According to this standard, when exposed to ultraviolet radiation, the spectral transmittance at laser wavelengths must not exceed the maximum permissible spectral transmittance of the relevant scale number.
Stability to high temperature: After exposure to high temperature according to this standard, the requirements of this standard shall be met.
Mechanical strength: Flexible sieves must withstand a tensile stress of 15 N/mm2 for 10 seconds when tested in accordance with this standard. No specimen shall tear after this test. Rigid sieves must be robust in accordance with EN 166. The sieves' fastening systems must be designed to remain attached to the sieves or the machine when the sieves are removed.
Resistance to ignition: Flexible screens must meet the requirements of EN 1598 when tested in accordance with EN 1598. Rigid screens must meet the requirements according to EN 166.

The test program in the table titled "Test program for screens providing protection against laser radiation" applies to testing flexible and rigid screens. A minimum of 18 samples is required for testing. More samples may be required if testing is required for multiple wavelengths (wavelength ranges) or for test conditions according to the above tables.

Spectral transmittance should be determined at the normal angle of incidence. Screens with angular transmittance should be measured with polarized radiation at angles of incidence between 0° and 90°. In this case, the scale number is obtained from the highest of the measured spectral transmittance values.

Laser radiation resistance tests should be performed with specific laser radiation wavelengths and power and energy densities. Spectral transmittance at the laser wavelength should be measured during laser radiation exposure.

In short, EN 12254 is a European standard that specifies the functional requirements, test methods, and labeling specifications for passive guards designed to protect against laser radiation in workplace environments. This standard is critical to ensuring safety in environments where laser equipment is used, such as manufacturing, research, or medical facilities. It addresses specific safety concerns within specified power and energy limits, focusing on protecting users from unintentional or limited-time exposure to laser radiation.

This standard applies to temporary and permanent passive screens designed to protect users from laser radiation in monitored workplace installations. It covers the following laser radiation:

Maximum average power 100 W or single pulse energy 30 J.
A spectral range of 180 nm (0,18 µm) to 1.000 µm (1 mm).

These screens are designed to protect against:

Unintentional exposure to direct or scattered laser radiation.
Time-limited exposure based on functional requirements determined by risk assessment.

This standard expressly excludes other hazards, such as secondary radiation from material processing, and does not cover laser enclosures or housings that are part of a laser product or system as defined in EN 60825-1. It provides guidance on the selection of suitable shielding, but is limited to laser radiation protection.

The EN 12254 standard contains rigorous test methods for assessing the functional performance of laser protective screens. These tests evaluate:

Optical performance: The ability of the screen to reduce or block laser radiation to safe levels.
Mechanical performance: The durability and stability of the screen under laser exposure.
Document control: Ensuring that user manuals and labels meet the requirements of the standard.

These tests differ from those in related standards, such as EN 60825, which focus on laser equipment safety and classification. EN 12254 specifically addresses the materials and performance of protective screens.

The EN 12254 standard applies to various laser protection elements, including:

Laser safety curtains (barriers or walls): Used to isolate laser work areas.
Laser safety curtains: Flexible barriers for temporary or adjustable installations.
Laser safety windows: Clear or translucent panels that provide visibility while blocking harmful radiation.

Consequently, EN 12254 is a cornerstone of laser safety, providing requirements for the design, testing, and labeling of protective screens in laser workplaces. Focusing on passive barriers, it addresses a critical aspect of workplace safety by providing protection against accidental or time-limited laser exposure. Organizations using lasers should consult this standard to ensure compliance and effectively protect personnel.

Our organization, which has been operating for many years and meticulously follows global developments in science and technology, employs a skilled team and extensive infrastructure to conduct testing, measurement, and analysis in a wide range of areas for businesses across all sectors. In this context, we also provide testing services in accordance with the EN 12254 "Screens for Laser Work Areas - Safety Requirements and Testing" standard.