10.	INVENTORIES.

The detail of inventories as of December 31, 2017 and 2016, is as follows:

	As of December 31,
	2017		2016
Classes of Inventories	ThCh$		ThCh$
Supplies for Production		16,879,260		12,377,179
Gas		2,301,172		2,159,901
Oil		2,593,806		2,556,438
Coal		11,984,282		7,660,840
Other inventories (*)		22,807,682		25,162,417
Total		39,686,942		37,539,596

(*) Other inventories		22,807,682		25,162,417
Supplies for projects and spare parts		12,311,718		17,076,698
Electrical materials		10,495,964		8,085,719

There are no inventories pledged as security for liabilities.

For the years ended December 31, 2017, 2016 and 2015, raw materials and consumables recognized as fuel expenses were ThCh$280,739,362, ThCh$295,148,838 and ThCh$327,502,996, respectively, See Note 26.

As of December 31, 2017, no inventories have been written down due to obsolescence.