Several towns in Batangas, Cavite, Laguna, and southern parts of Metro Manila suspended classes on Friday, 22 September due to the health hazards brought by the volcanic smog or vog emitted by Taal Volcano.

Here is the list of municipalities that canceled classes today:

Batangas (all levels; public and private):

Balayan, Balete, Calaga, Calatagan, Lian, Nasugbu, Lemery, Tanauan City, Taal, Tuy, San Nicolas

Cavite (all levels; public and private):

Alfonso, Amadeo, Bacoor City, Carmona, Cavite City, Dasmariñas City, Gen. Emilio Aguinaldo (Bailen), Gen. Mariano Alvarez, Gen. Trias, Indang, Imus, Kawit, Magallanes, Mendez, Maragondon, Naic, Noveleta, Rosario, Silang, Ternate, Trece Martires, Tagaytay City, Tanza.

Laguna (all levels; public and private): 

San Pedro

Metro Manila (all levels; public and private):

Las Piñas and Muntinlupa.

Taal's volcanic smog

According to the Philippine Institute of Volcanology and Seismology in its advisory on Thursday afternoon, the vog coming out of Taal contains a high amount of sulfur dioxide which is acidic and can cause irritation of the eyes, throat, and respiratory tract.

"People who may be particularly sensitive to vog are those with health conditions such as asthma, lung disease, and heart disease, the elderly, pregnant women and children," the advisory said.

The advisory also asks the public to limit outdoor activities, shut the doors and windows to block out the vog, wear an N95 facemask, and drink water to reduce any throat irritation or constriction.