Non-halogenated Flame Retardant Handbook. Группа авторов

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).

1.3 Current Regulations

      As previously discussed, regulations are often reactive based upon past historical events in a particular location where local or national fire events drive new requirements to prevent a particular fire event from happening again. Likewise, local cultural uses of building products, building styles, and operating of technology may drive particular fire safety requirements, especially if there are local population density issues, or environmental effects (earthquakes, wildfires) that may drive fire safety requirements in one direction or another. Therefore, regulations are be best discussed at the national and regional level.

      1.3.1 International – United Nations

      Legacy halogenated flame retardants have meanwhile been restricted under the United Nations Persistent Organic Pollutants (POP) convention: HBCD, PBDEs including DecaBDE, and short-chain chlorinated paraffins (SCCP) [43].

1.3.2 United States (Federal vs. State)

      In the United States (US), federal government regulations overrule state regulations. However, if there is no specific federal regulation on a particular topic or chemical, then state regulations apply. This can mean that a product sold in the US could have to meet 50 different state regulations if they are different. Currently, most chemicals are regulated by the Toxic Substances Control Act (TSCA, 1976) which was “updated” by the Frank R. Lautenberg Chemical Safety Act for the 21st Century in 2016. Under TSCA, only very few chemicals were banned and it generally took many years. Regarding flame retardant chemicals, there have been voluntary phase outs of brominated diphenyl ethers in the US due to rulemaking and agreements with the US Environmental Protection Agency (EPA), and some scrutiny of hexabromocyclododecane (HBCD), [44–49]. The US EPA set up a workplan on flame retardants already in 2012 but with slow progress. In March 2019 they concluded TCEP, TBBPA and TPP as “high priority substance” candidates for risk assessments.

      In addition to these regulatory workstreams, from 2005 to 2015, the US EPA did run a serious of extensive Design for Environment (DfE) projects which evaluated alternatives to the legacy brominated flame retardants pentabromo- and decabromo diphenylether, hexabromocyclo dodecane and tetrabromo bisphenol-A [50]. The conclusion was that often halogen free alternatives exist with a better environmental and health profile. Furthermore, in 2017 the US Consumer Product Safety Commission (CPSC) voted to initiate rulemaking based on a petition to protect consumers from “toxic” flame retardant chemicals commonly referred to as organohalogens (OFRs), under the Federal Hazardous Substances Act [51]. The initiative refers to children’s products, furniture, mattresses, and electronic device casings. CPSC further advised setting up a Chronic Hazard Advisory Panel to further study the effects of OFRs as a class of chemicals on consumers’ health. The petition lists 24 organohalogens including decabromodiphenyl ether and several chlorinated phosphate esters, believed to be toxic, that tend to migrate out of products, and can bioaccumulate.

At the state level however, there has been a lot of regulatory movement to ban flame retardant chemicals by broad chemical class, rather than by specific molecule. Most of the bans are focused around keeping flame retardant chemicals out of mattresses and furniture, but some bans on manufacture and use of flame retardant chemicals are broader in scope than just furniture and mattresses. The wide range of state regulations is far too much to cover in this chapter, and a reasonable summary of each rule with links to each state law is available online [52]. That being said, the emphasis of most state laws is to ban flame retardants by class (halogen, phosphorus, nitrogen, etc.) in specific consumer products (mostly furniture and mattresses) rather than by specific chemistry. If TSCA change does occur which lists particular flame retardants as safe/not safe to use, that TSCA change would overrule all of the individual state laws. Otherwise, it is highly recommended that material scientists work with their respective regulatory experts if they are planning on using any flame retardant chemical for products in the US, whether halogenated or not. As of the writing of this chapter, the situation is still very uncertain how these state laws will move forward, or if they will get challenged and found to be unworkable by generating broad bans of chemical classes vs. specific negative PBT profile chemicals.

      1.3.3 Canada

      Chemical regulation in Canada is governed by the Canadian Environmental Protection Act (CEPA) [53] as well as new substances/existing substance under its Chemical Management Plan. Flame retardant chemicals which are regulated under this law include brominated diphenyl ethers (BDPEs), hexabromocyclododecane (HBCD), and tetrabromobisphenol A. As per the law, new chemicals are investigated and added to the regulatory list as PBT data becomes available.