The harmful pollutants emitted from vehicles are varied. The specific toxic gases that are a cause for concern environmentally, as well as due to their impact on human health, specifically in underground and multi-storey car parks, are CO and NO2.
Underground and multi-storey car parks generally have a lack of natural ventilation, which means that higher levels of these gases can be concentrated in one area and, therefore, can have a more harmful impact on those within these environments because they are not easily dispersed.
The European Standard EN 50545-1 specifies requirements for remote gas sensors (RGS) and control units (CU) to be used in car parks because of this.
The main gases found within car parks are Carbon Monoxide (CO) and Nitrogen Dioxide (NO2). These gases are of particular concern due to their characteristics. CO is dangerous as it is colourless and odourless, which therefore makes it hard to recognise without the proper monitoring equipment. CO is damaging even at low exposure levels, again making it a real cause for concern, even when there are only slight concentrations present in a space.
Nitrogen Dioxide is also harmful at low exposure levels, and both NO2 and CO can cause a variety of negative health effects. When ingested, Carbon Monoxide poisoning can cause headaches, dizziness, sickness, nausea, feeling weak, disorientation and confusion, chest and muscle pain, alongside shortness of breath. These symptoms can fluctuate and will worsen when in a space where the toxic gas is present, and may improve when you leave it.
Nitrogen Dioxide also has a harmful effect on humans when breathed in, at the worst it can cause premature death. Other symptoms include cardiopulmonary effects, decreased lung function growth, respiratory issues, and heightened complications for allergic responses.
With such serious effects when ingested, it is incredibly important for proper monitoring in spaces with these gases present, including car parking areas.
Ventilation is incredibly important as it is the key to ensuring that gas levels are kept to acceptable levels, as well as being the way to ensure the prevention of the buildup of toxic fumes. Using detectors, ventilation can be linked to gas levels which can, for example, allow ventilation to be increased when gases (CO or/and NO2) reach a certain level, as well as decreased when gases are at acceptable levels.
This type of gas detection and ventilation can, in turn, lead to increased energy efficiency for the car parking operations utilising them, which can have a positive knock on effect on the business’s bottom line.
The UK’s building regulations 2010 provide guidance on the necessary ventilation required for car parks below ground level, enclosed car parks and multi-storey car parks, and are a handy starting point when it comes to choosing the type of system which can be implemented into car parking spaces.
According to the European Standard listed above (5045-1), CO alarm levels and maximum thresholds should be set at 30 ppm as Alarm 1, 60 ppm as Alarm 2 and 150 ppm as Alarm 3. The standards states NO2 thresholds will be set at 3 ppm as Alarm 1, 6 ppm as Alarm 2 and 15 ppm as Alarm 3.
Elsewhere in the UK’s building regulations 2010 it is suggested that CO should be limited to an average concentration of a maximum of 30 parts per million over an eight-hour period. With a peak concentration, such as by ramps and exits, at a maximum of 90 parts per million over a 15-minute period.
International regulations recognise the danger posed by NO2 and CO in car parking spaces, with the European Standard EN 5045-1 referring to apparatus for the detection and/or measurement of carbon monoxide (CO), nitrogen monoxide (NO) and nitrogen dioxide (NO2). This standard details the requirement for the control of a ventilation system within hazardous spaces, as well as the need to give an indication, alarm or any other signal to warn of a toxic hazard. NO2 and CO form two of the three three “target gases” referred to within this European Standard.
The 5045-1 European Standard mandates that remote gas sensors (RGS) should be used in car parks and tunnels, alongside denoting the requirements for control units (CU) to be used in car parks. It also refers to monitoring in other spaces where these gases could pose a risk to human health, such as within loading areas for trucks and underground bus stations.
The UK’s Building Regulations 2010 is also of importance when it comes to the monitoring of toxic gases within car parking areas, as it lays out guidance on the adequate ventilation of car parks. The regulations state that underground, enclosed and multi-storey car parks should have a designed ventilation rate, and the appropriate equipment needs to be installed, in order to limit carbon monoxide to an average concentration of a maximum of 30 parts per million over an eight-hour period, and peak concentration, such as by ramps and exits, of a maximum of 90 parts per million over a 15-minute period.