VOC (Volatile Organic Compound) limit standards for phenyl silicone seals in the automotive industry are important regulations for ensuring in-vehicle air quality. The following is a detailed description of the relevant standards:

I. Major VOC Substance Limit Standards
‌Chinese National Standards‌:
According to the "Guidelines for Passenger Car Indoor Air Quality Assessment" (GB 27630-2011), the following are stipulated:
Benzene ≤ 0.11 mg/m³
Formaldehyde ≤ 0.10 mg/m³
Toluene ≤ 1.10 mg/m³
Xylene and ethylbenzene ≤ 1.50 mg/m³
Styrene ≤ 0.26 mg/m³
Acetaldehyde and acrolein ≤ 0.05 mg/m³

‌EU Standards‌:
REACH Regulation (effective August 6, 2027):
Indoor formaldehyde concentration limit for vehicles: 0.062 mg/m³
Testing standards are ISO 12219-1 or ISO 12219-10

TVOC (Total Volatile Organic Compound) Limits:
National standards stipulate that the TVOC concentration in vehicles must be <0.60 mg/m³.
Some OEMs have stricter requirements, such as <0.30 mg/m³ for certain models.

II. Test Methods and Standards
International Test Standards:
ISO 12219 series: Specifies VOC test methods for automotive interiors.
German VDA 270-275-277 series of test methods (including odor testing, formaldehyde testing, and total carbon testing).

Chinese Test Standards:
HJ/T 400-2007: Sampling and Determination Method for Volatile Organic Compounds and Aldehydes and Ketones in Vehicles
Test Conditions: 25.0±1.0°C, Relative Humidity 50±10%
Test Method: Collect air samples after sealing for 16 hours

OEM-Specific Test Methods:
Volkswagen PV3938 Standard: Tested using infrared light to a surface temperature of 65°C
Japanese Bag Method (Bag-TD-GC/MS): VOCs collected using a sampling bag

III. Special Requirements for Phenyl Silicone Seals
Material Selection:
Low-VOC raw materials should be selected, such as:
Aromatic-free white oil or low-aromatic paraffin oil as a softener
Carbon black with a low iodine absorption value as a reinforcing agent
Non-nitrosamine curing system

Production Process Control:
Process conditions such as ambient temperature and vehicle usage time can affect VOC emissions. Optimizing the production process is necessary to reduce overall VOC emissions.

OEM-Specific Requirements:
Each OEM has more stringent VOC requirements for sealing materials. VDA approval is generally required. 270 Odor Test and VDA 275 Formaldehyde Test

IV. Industry Development Trends
Increasingly Stringent Standards:
China's GB 27630-2011 standard has been upgraded from a recommended standard to a mandatory standard.
EU REACH regulations will lower the formaldehyde limit to 0.062 mg/m³.

Application of Environmentally Friendly Materials:
OEMs are increasingly using environmentally friendly resin damping pads and water-based adhesives. Brands like Lynk & Co and Volvo have pledged to use environmentally friendly sound insulation materials across their entire lineup.

Testing Technology Developments:
Evolving from whole-vehicle testing to material-level testing.
Testing conditions are now closer to actual operating environments (e.g., high-temperature testing).