The Hazardous Substance Tax (HST) is a tax on the possession of hazardous substances in Washington. The tax is imposed on the first possessor of the hazardous substance in Washington.
With regard to agriculture and farming, HST applies to many pesticides, petroleum products, and chemicals.
Are farmers exempt from this tax?
In general, farmers are not exempt from this tax. The tax is on the first possessor of a hazardous substance, and does not continue to subsequent possessors, as long as the tax has been paid. If you purchase hazardous products from an in-state supplier, your billing from the supplier may indicate that the HST was paid and that it is being passed on to you.
If you purchase the hazardous substance from an out-of-state supplier who has not paid Washington's HST, then you owe the tax as the first possessor in this state.
How do I pay the tax?
The tax is reported on the Excise Tax Return. There are two separate lines on the return to report each HST rate.
What rate do I pay?
The rate is .007 (seven-tenths of one percent) of the wholesale value of the hazardous substance.
- Non-petroleum products—including many pesticides, rodenticides, and fungicides, or other chemicals with environmental impacts—as well as petroleum products that are not easily measured on a per-barrel basis, are subject to a rate of 0.7 % (.007) multiplied by the wholesale value of the product. For these products, use the Hazardous Substance Tax by Value line (line code 65).
- Petroleum products are subject to a rate of $1.13 per barrel (42 gallons), unless the product is not easily measured on a per barrel basis. For these products, use the Hazardous Substance Tax by Volume line (line code 81).
See our Hazardous Substance Tax publication for more information on how to report this tax.