The standard green grass found in Australian paddocks and lawns. During spring and summer, it sheds massive yellow clouds of tiny grains that stick inside your nose.

When high humidity and rain clouds suck up grass pollen, water forces the grains to burst into hundreds of micro-fragments that fly deep into airways.

Tiny specks of car exhaust, bushfire smoke, and industrial soot that are 30 times thinner than a single strand of human hair.

A super-dense mat of tangled glass fibres used in medical purifiers. It traps microscopic pollen and dust like a fly caught in a spiderweb.

A chemical your immune system releases when it mistakenly thinks harmless grass pollen is a dangerous virus or poison. It triggers sneezing to blow it out.

A natural lipid balm or microgel dabbed around your nostrils before heading outside. Pollen sticks to the balm instead of your sensitive skin.