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With some basic history about halogenated and non-halogenated flame retardants in place, we can now discuss more detailed regulation of flame retardants. In general, regulations are mostly reactive to information and events, rather than proactive to potential or perceived hazards. There are exceptions, but this reactive mode of regulation is applied in the majority of regulatory cases.

Modern fire safety regulations are often found within various legal codes, especially building codes, aviation regulations, and federal registers that describe particular requirements and test methods to ensure fire safety in a structure, vehicle, component, sub-component, or material. These regulations do not require any particular flame retardant chemistry to be used, but instead prescribe a particular level of performance. In fact, regulations really do not mandate flame retardants to be used at all. Flame retardants get used because it is one of many ways to provide fire protection, and may be selected depending upon all the other “non-fire” requirements for a functional item, including cost, thermal/mechanical/electrical performance, manufacturing requirements, intellectual property, and so on. It is important to emphasize this point as there is some perception that fire safety regulations mandate or push the use of flame retardants. This is not correct. The only time a particular chemical will be mandated for use is when it is prescribed in a manufacturer requirement document after certifications for use have been achieved. For example, a composite part inside the cabin of an aircraft that meets flame spread and heat release requirements and has been deemed “airworthy” may have manufacturer requirements to hold to a particular polymer formulation to ensure the part meets the requirements and does not have to be recertified for use. This requirement may then specify specific flame retardant chemicals, and loading levels, to meet the performance. But again, if one reads the original fire safety requirements, the original laws will not mandate any particular approach or chemical to be used.

Fire safety regulations will seek to mimic a particular fire risk scenario where there has been a notable hazard identified, and some probabilities of that hazard occurring with notable loss of life or property. Within the regulation is a test method that seeks to mimic the fire risk scenario, and validate, in a reproducible way, that the item does meet the fire safety goals of the regulation. This typically means pass/fail test methods, but sometimes it can be a quantitative test that assigns levels of fire safety to the item tested depending upon that measured quantity. For example, different fire safety classes may be assigned to some building materials depending upon their ability to resist various heat sources, as well as levels of flame spread and smoke release. Therefore, for anyone to be able to sell a product into an application that has a fire safety requirement, one must test their materials via the regulatory test method. If the material should not pass the test, then flame retardant or fire protection methodology may be required. This is where flame retardants often get introduced into products, when the product tested does not meet the fire safety test. Flame retardants will not be added to a material if the material already passes a fire test, as it just adds cost and complexity to a material. Flame retardants will be added to the material if it enables that material to pass the particular regulatory test and it meets all the other product requirements. Sometimes, flame retardants are not needed if simple engineering controls can be used to provide fire protection for the item. Examples of engineering controls can be isolating the flammable material from ignition sources or using sprinkler systems. However, when flame retardant additives are used, they are tailored for each fire risk scenario and for each material – they are not universal and cannot be swapped from material to material without careful consideration. Therefore, one must study each specific material in each specific fire risk scenario to know what flame retardant chemical to use. This chapter will not see to cover the wide range of fire risk scenarios and test methods, as there are other excellent resources for this [9, 14, 40–42, 57]. Instead, keeping in mind that specific flame retardants get used for specific materials in specific fire risk scenarios, we can discuss flame retardant chemical regulations.

Returning to the historical perspective of flame retardancy for a moment, many of the older flame retardants now banned were used for decades because they worked very well in a particular material to provide fire protection against a particular fire risk scenario. Just as new information can come to light on the PBT profile of a chemical which will affect its use, fire risk scenarios can change over time. However, in other cases, the fire risk scenario may remain the same, but particular chemicals or classes of chemicals may be regulated differently. As discussed previously, halogenated flame retardants have been heavily regulated in recent years due to concerns about their dioxin formation, as well as specific PBT issues. So in more recent times, there are regulatory changes to which chemicals may be used, while not changing the regulatory fire test, and in other cases, the regulatory change is made to the fire test and to the chemicals allowed to be used. As will be discussed below, there have been approaches taken to dis-incentivize the use of flame retardant chemicals through other product regulation, while maintaining the need for particular fire safety, or, to change the fire safety regulations themselves. When the latter is chosen, the current approach has been to lessen the fire safety requirements. While there can be changes in fire risk scenario that can support this approach, as will be discussed below, sometimes the change in fire risk scenario is driven by perceptions and political considerations, and not actual fire safety requirements. Fundamentally, the assessment of fire risks for certain products like upholstered furniture should be done separately from the chemical safety assessment of flame retardants which might be used. Reducing fire safety requirements to get rid of “unwanted” FRs is the wrong approach, as one should rather restrict the use of any problematic chemicals directly and promote the use of safer alternatives (see detailed discussion below).