Each time a woman buys a tampon or pad in Colorado, she pays sales tax. It’s just a cost of being female.

That’s not fair, says a state lawmaker who introduced legislation to exempt these and similar feminine hygiene products from state sales taxes. The proposal in the Colorado legislature, House Bill 1127, follows the lead of a handful of other states that have done so in recent years.

“It doesn’t seem fair to me that we tax something that women have to have, for a bodily function that we cannot control,” said Rep. Susan Lontine, D-Denver, who sponsored the bill.

Supporters of eliminating the so-called “tampon tax” say it’s part of a broader push for gender equality. And sales taxes on menstrual hygiene — while they don’t cost much — represent a striking example of something women have to pay just because they’re female.

Looking beyond tampons, consumer studies have found that products marketed to girls cost as much as 7 percent more than the equivalent products marketed to boys. That includes a wide range of consumer goods, such as deodorant, razors, hair-care products, toys and clothing.

“We pay more for haircuts, we pay more for dry cleaning, we pay more for similar items of clothing and we typically make less than men,” Lontine said.

Her bill, which narrowly cleared the House Finance Committee on Monday, won’t address price disparities in the market, but she said it would provide a small boost to women who unfairly pay more for other products. In all, seven states explicitly exempt menstrual products from sales taxes, and Connecticut would become the eighth when a law it passed recently takes effect in 2018.

But not all women were on board with the idea. State Rep. Polly Lawrence, R-Douglas County, questioned why menstrual products should be singled out when other hygiene products that people need are still subject to sales tax. In Colorado, unlike some other states, adult and baby diapers are taxed. So are toiletries used by everyone, such as tissues and toilet paper.

The discussion underscored the complexities — and inconsistencies — of state tax law. In Colorado, over-the-counter drugs are taxed, but prescription drugs are not. Most groceries are tax free — but not candy, or pre-packaged salads and sandwiches. To-go boxes are taxed if it’s a carry-out order — but not if you take home part of a meal you started eating at the restaurant.

A few industries even get special sales tax breaks: solar panels, wind turbines and other renewable energy equipment are sales tax free. So are space shuttles and other equipment used in spaceflight.

Exempting tampons would cut state sales tax collections by $2.4 million annually, according to the Colorado Legislative Council, but because of a quirk on Colorado tax law, the state actually wouldn’t see a drop in revenue under today’s financial conditions. Because the state is collecting more tax dollars than it’s constitutionally allowed under the Taxpayer’s Bill of Rights, a $2.4 million sales tax cut would be offset by a $2.4 million cut in taxpayer refunds.

That may sound like a lot of money, but the average Colorado woman wouldn’t see much relief. According to the fiscal analysis, that would round out to about $1.71 in annual savings per woman. And she would be exempt only from the 2.9 percent state sales tax. Local governments, which collect the bulk of Colorado’s sales taxes, would not be affected by the bill.

A tax analyst with the Colorado Fiscal Institute, a left-leaning fiscal policy group, urged lawmakers to consider comprehensive state tax reform, saying she supported efforts to make the tax code fairer, but was neutral on the bill.

“We’re just picking away at our revenue structure” through piecemeal exemptions, said Ali Mickelson, director of tax and legislative policy at CFI. “We think it’s time … to put everything on the table and then decide what makes sense and what does not.”

Next up for the bill is the Appropriations Committee. If it clears the committee stage and ultimately passes the Democrat-controlled House, it would likely face skepticism from the GOP-controlled Senate.

The committee vote was split along party lines, 7-6.