Child Safety Rear Door Locks
When the child lock is engaged, the interior handle is rendered useless, usually just moving freely without unlatching the door. In this state a passenger simply cannot open the door, nor can he or she disable the lock, and is effectively locked in. The door can only be opened by someone lifting the outside handle, either a second person or by the passenger opening the window and reaching the outside handle.
In the United States, child safety locking mechanisms have been required by law since 1970 on all containers for potentially dangerous medicines and household cleaning products. These laws are enforced by the Consumer Products Safety Commission. These locking mechanisms may take several forms, but the most common is a design that requires a tab to be pressed firmly as the lid is twisted. Great strength and dexterity are not required to open the bottle, but the process is deliberately made to be unintuitive, and the children who might recklessly eat pills are unable to decipher the opening instructions. Parents and guardians are firmly admonished  to keep all such containers out of the reach of children anyway, as no locking device is foolproof. It has become common practice in households to keep medicines and pills in high cabinets (sometimes locked) for safety. Cleaning agents, however, are still generally kept under sinks, where they are accessible.
Another type of lock is an inexpensive device which can be easily installed into drawers, cabinets, or other openables to prevent easy opening. It consists of a bendable plastic rod with a blunt hook on one side, and is situated on the inside of the drawer or cabinet. The hook catches on part of the drawer or door and prevents opening unless the rod is bent downward simultaneously to disengage the hook. These devices are helpful to pet owners as well — a typical housecat may be able to paw open a cabinet filled with food, but would have trouble operating the hook mechanism. Also available are electromagnetic cabinet locking devices that are activated via remote control.
Child safety locks are built into the rear doors of most cars to prevent rear seat passengers from opening the doors both during transit and while the vehicle is stationary; vehicles have been built with this feature since the early 1980s. They provide the vehicle driver with a simple, safe & secure method to prevent unauthorized exit from the car. Although called a child lock it is equally effective for adult passengers.
Certain locks are available specifically for child proofing. These locks have the same function as the other lock design: to lock away valuables, food, or dangers from unwanted guests. However, these locks have a design that resembles a strap like lock. It attaches with two adhesive stickers and opens with a small slider. This slider was specifically designed to be tough for smaller children to get open, such as the medicine/cleaning product containers. Because of its latch design, it is not only able to strap to cabinets, but also other objects of the like. This includes but is not limited to fridges, toilets, garbage cans, drawers, microwaves, etc...