DENVER -- Colorado is filing suit against the Department of Defense, hoping to force the Army to destroy obsolete chemical weapons stored in the state by 2017.

The military has said it could take until 2023 under current funding and staffing levels to eliminate about 2,600 tons of mustard gas stored at the Pueblo Chemical Weapons Depot near Pueblo.

The military says the weapons are outdated and have no military use. The state says the gas is still highly toxic and can cause severe skin and lung inflammation, cancer and birth defects.

The Colorado Department of Public Health and Environment said Tuesday it had filed suit in Denver federal court. Court officials said they had not yet seen the lawsuit.

A military spokeswoman did not immediately return a call. The Army has said previously it wants to destroy the Pueblo stockpile as safely and quickly as possible.

State health officials said Colorado regulations bar long-term storage of hazardous waste unless additional quantities are being accumulated for proper treatment, or an alternative schedule has been approved.

The state health department says it has regulatory power over the Army's plans to destroy the weapons, and in June the state issued an administrative order calling for the Defense Department to destroy the weapons by 2017.

Officials said Tuesday they decided to sue in federal court because the military plans to appeal the order.

"Given recurring delays by the Department of Defense for completing treatment and destruction of these wastes, the division is seeking an enforceable schedule for their timely treatment. We believe the 2017 deadline is more than reasonable to complete treatment and destruction of the chemical weapons," said Gary Baughman, director of the Hazardous Materials and Waste Management Division of the Colorado health department.

The Army also has chemical weapons stored at the Blue Grass Army Depot in Kentucky.

Mustard agent is an acutely toxic hazardous waste causing severe skin and lung inflammation, which is known to cause cancer and birth defects.

For more information about the Pueblo Chemical Depot chemical weapons destruction, go to the Colorado Department of Public Health and Environment Web site.