Thread: Hydrogen Cyanide Gas Affects 4 villages in Chiang Rai

The foul odour caused by hydrogen cyanide (HCN) from a lime stone factory in Myanmar has affected four villages in the Mae Sai district of Chiang Rai province.


The factory,registered as Ban Lom It 999, is located in Myanmar’s border town of Tachileik, opposite Mae Sai.


According to reports, the toxic gas emitted from the site sent a foul odour adrift, upsetting about ten nearby villages in tambon Mae Sai and Koh Chang.

Mr. Narongphol Khid-arn, the district chief of Mae Sai, has established an emergency operation centre to alert village leaders to the toxic gas in adjacent tambons. He also advised residents to wear masks and close their windows at night.


HCN gas is a colourless, highly toxic gas that is commonly used in pest control and gold mining. Direct contact may harm the bronchi, lungs, brain, heart, and blood vessels.

The pollution has affected 4 Chiang Rai villages in tambon Mae Sai: Muang Daeng Tai, Wiang Hom, San Sai, and San Sai Mai.

The Environmental and Pollution Control Office 1 (Chiang Mai) used a portable gas detector, which revealed that the HCN level had increased to 0.5 parts per million (ppm) from 0 ppm, which is considered harmful to the respiratory system.

The odour spread to Bang Chong in tambon Pong Pha on Wednesday night, about 13 kilometres from the Myanmar – Chiang Rai border.


Through the Thai-Myanmar Township Border Committee, the Chiang Rai Department of Provincial Administration and the army coordinated with Myanmar authorities.

Hydrogen Cyanide Gas Affects 4 Villages In Chiang Rai

The foul odour caused by hydrogen cyanide (HCN) from a lime stone factory in Myanmar has affected four villages in the Mae Sai district of Chiang Rai province.

I would imagine it's affected a few in Myanmar as well. FFS.

Originally Posted by misskit

The foul odour caused by hydrogen cyanide (HCN) from a lime stone factory in Myanmar has affected four villages in the Mae Sai district of Chiang Rai province.

According to reports, the toxic gas emitted from the site sent a foul odour adrift, upsetting about ten nearby villages in tambon Mae Sai and Koh Chang.

Was it 10 or 4? Just 4 have health issues, but only upsetting 10?

Thanks for posting, I was warned about this a while back and it was reported in the Thaiger recently with more detail.
AFAIK the border bounce is still off so there is no need for foreigners to visit at present.

If you need a border bounce the friendship bridge 5m South of Chiang Khong to Lao is an option for crisp clean untorn US$30-42 depending on nationality (if you pay in baht its about 1600-2000 .Please note Lao eVISA takes less space n passport.

Last time I drove a Czech mate and waited she was back in under an hour, as fast as Tachilek.
You are not allowed to walk or cycle over must use the shuttle bus

Residents in a Chiang Rai district forced to breathe poisonous hydrogen cyanide for months | Thaiger

It is a horrible gas

Hydrogen cyanide has been known as a potent toxicant for over 200 years. It was used as a chemical warfare agent during World War I by France.

Originally Posted by misskit

Hydrogen Cyanide Gas Affects 4 villages

Thought the Chinese had already started their Conquer Then Genocide policy for a sec.