Liquid crystal display screens as a source for indoor volatile organic compounds

Area of Science:

• Environmental Science
• Indoor Air Quality
• Analytical Chemistry

Background:

• Liquid crystal displays (LCDs) are ubiquitous in modern life.
• The impact of LCDs on indoor air quality remains largely unknown.
• Understanding emissions from electronic devices is crucial for public health.

Purpose of the Study:

• To investigate the potential emission of air constituents from LCD screens.
• To identify and quantify volatile organic compounds (VOCs) and liquid crystal monomers (LCMs) released from LCDs.
• To explore the influence of indoor humidity on these emissions.

Main Methods:

• Flow cell experiments were conducted on three different LCDs (new monitor, used laptop, new TV).
• Emitted volatile organic compounds (VOCs) and liquid crystal monomers (LCMs) were identified and quantified.
• The effect of varying indoor humidity levels (23% to 58%) on emission rates was analyzed.

Main Results:

• Over 30 volatile organic compounds (VOCs) were detected, with emission rates up to (8.25 ± 0.90) × 10^9 molecules·s^-1·cm^-2.
• Ten liquid crystal monomers (LCMs) were identified as being released from the LCD screens.
• Emission rates of VOCs and LCMs increased by up to a factor of 9 with rising indoor humidity.

Conclusions:

• LCD screens are a previously unrecognized source of indoor volatile organic compounds (VOCs).
• Liquid crystal monomers (LCMs) are also emitted, contributing to indoor chemical exposure.
• Indoor humidity plays a significant role in enhancing the diffusion and emission of these organic compounds from LCDs.