If a relatively high level of carbon monoxide is detected, the device sounds an alarm, giving people the chance to evacuate and ventilate the building. Unlike smoke detectors, carbon monoxide detectors do not need to be placed near ceiling level. The use of carbon monoxide detectors has been standardized in many areas. In the US, NFPA 720–2009, the carbon monoxide detector guidelines published by the National Fire Protection Association, mandates the placement of carbon monoxide detectors/alarms on every level of the residence, including the basement, in addition to outside sleeping areas. In new homes, AC-powered detectors must have battery backup and be interconnected to ensure early warning of occupants at all levels. NFPA 720-2009 is the first national carbon monoxide standard to address devices in non-residential buildings. These guidelines, which now pertain to schools, healthcare centers, nursing homes, and other non-residential buildings, include three main points:
1. A secondary power supply (battery backup) must operate all carbon monoxide notification appliances for at least 12 hours,
2. Detectors must be on the ceiling in the same room as permanently installed fuel-burning appliances, and
3. Detectors must be located on every habitable level and in every HVAC zone of the building.Gas organizations will often recommend getting gas appliances serviced at least once a year. Legal requirements
The NFPA standard is not necessarily enforced by law. As of April 2006, the US state of Massachusetts requires detectors to be present in all residences with potential CO sources, regardless of building age and whether they are owner-occupied or rented.
Brachioradial pruritus (sometimes abbreviated BRP) is an intense itching sensation of the arm usually between the wrist and elbow of either or both arms. : 36   The itch can be so intense that affected individuals will scratch their own skin to a bleeding condition. The condition is becoming increasingly common, presenting in patients who are usually fair skinned and middle aged and indulge in golf, tennis, outdoor table tennis, sailing,  or other leisure outdoor activities in sunny climates. : 64 : 402 The cause is not known, although there are a few lines of thought on what causes it. No cure has been found, but depending on severity, good control with treatment can be achieved. For milder cases, the intense itch/scratch cycle can be broken by applying a topical skin coolant gel containing menthol, camphor, or other topical coolant to affected itchy areas, and then consistently applying 100+SPF sunscreen to affected skin of arms, shoulders, neck, etc., whenever they are expected to be exposed to the sun. A unique prescription topical combination of ketamine .5% and amitriptyline hydrochloride 1% has shown immediate and long term relief with no serious adverse events in at least one severe case. [1]
Many different medications and types of topical creams have been experimented with, but few seem to make any difference, except for the above. The application of ice packs to the affected area can also diminish the itch short-term. Causes
Brachioradial pruritus (BRP) is a localized pruritus of the dorsolateral aspect of the arm.