U.S., although some states such as Pennsylvania and New Jersey require that inflatables pass engineering and safety standards before allowing the equipment to be rented out. In 2017, roughly 25 U.S. states had regulations governing permits, inspections and insurance, although a private investigation by the Pew Charitable Trust has shown significant shortcomings by industry operators and regulators to do their part. North Carolina requires amusements rides, including inflatables, to be inspected annually by the North Carolina Department of Labor (NCDOL). For inflatables to pass inspection, operators in North Carolina are required to have all training records, a current certificate of insurance, and device manuals. Inflatables that are damaged and not safe will not pass inspection until they are repaired. Inflatable obstacle courses There are also inflatable obstacle courses that allow for participants to have races/sword fights and compete against one another. These are commonly rectangular in shape, but can also be square if the course is maze-like. Most obstacle courses have two lanes, but some can have three or four. They feature various such as pop-up obstacles, climbing areas, slides, and tunnels. These are the best choice for very large events since participants move through them quickly. Inflatable park The phrase "inflatable park" may refer to both a collection of portable inflatables set up temporarily as one attraction, or a permanent attraction consisting of inflatables. Games Some inflatables are designed to allow games such as boxing rings, water football, penalty shootouts, basketball, rumbling, tug of war, and gladiator duels. These interactive inflatable games are made out of the same material that a continuous airflow bounce house is made of. Quad tracks are also popular and provide the perimeter for quad bike racing. Safety Injuries are common. According to Jim Barber, spokesman for the National Association of Amusement Ride Safety Officials, "It happens all the time. These are probably the most dangerous amusement devices they have. You see more injuries on inflatables than almost any other amusement ride you can think of – more than roller coasters." In 2010, "as many as 31 U.S. children per day were treated for injuries sustained in a bounce house, or one child every 46 minutes." An estimated 65,000 children under the age of 17 were injured from 1990 to 2010. In May 2001, the U.S. Consumer Product Safety Commission released a bulletin outlining the dangers and recommended safety precautions for operating an inflatable structure.