Non-halogenated Flame Retardant Handbook. Группа авторов

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СКАЧАТЬ potential regulations from country to country can be quite different. The three main markets with chemical regulations related to flame retardants are China, Japan, and Korea, but it is likely that other Asian countries have or will develop chemical regulations that also cover flame retardants.

      1.3.6 China

China released its own version of RoHS in 2007 which is based upon the EU RoHS [55], but it only applies to imported materials, not exported electronics. It’s important to note that items exported from China to other parts of the world may have chemicals of concern that are banned from use in those countries. In the US for example, there have been several cases of imported goods from China containing chemicals (flame retardants and otherwise) that were banned from use in the US. There are even companies in China which produce flame retardants that are no longer produced in the US and EU because of their negative PBT profiles. It is unclear at this time how the China flame retardant regulations are enforced for domestic vs. export items, but local translation and guidance on Chinese environmental regulations is strongly recommended prior to selling into the Chinese market, or, getting exports of items potentially containing flame retardant chemicals from the Chinese market. An updated version of the China RoHS was issued in 2016, restricting the same six substances as the original EU RoHS. Products and parts that contain restricted substances exceeding limits can still be sold in China but need to be marked as such. A peculiar concept of China RoHS is the “Environment Friendly Use Period” (EFUP) designating the time before any of the RoHS substances might to leak out, causing possible harm to health and the environment. Every product that contains RoHS substances above the maximum permitted concentration is carries an orange circle label composed of two arrows containing a number that indicates the EFUP in years.

      1.3.7 Japan

      In Japan, the Ministry of Economy, Trade, and Industry manages the Chemical Substances Control Law (CSCL) [56] that would govern any use of flame retardant chemicals in that country, both in regards to manufacturing for domestic use and for export. The list of controlled chemicals on the CSCL is extensive, and does include some of the older flame retardants banned in the US and EU, such as brominated diphenyl ethers (BDPEs) and hexabromocyclododecane (HBCD) [57]. The CSCL and list of chemicals is updated from time to time and should be monitored for changes.

      1.3.8 Korea

In South Korea (Republic of Korea), chemicals (including flame retardants) are governed by the Toxic Chemicals Control Act [58]. This act controls the manufacture and use of chemicals in Korea, and new chemicals introduced into commerce in this country as well as any new chemicals made domestically in South Korea. At the time of writing this chapter, gaining access to this list of chemicals in English was not possible for the author of this chapter, so it is unclear if flame retardants are on the list of controlled chemicals. However, given that this law conducts analyses of chemical safety similar to other countries which have banned HBCD, BDPEs, and various metals like Cd and Cr, it seems highly likely that flame retardants with known/established negative PBT profiles are regulated and banned from use in South Korea. Those selling into the South Korean market are encouraged to check the local regulations and see which chemistries are banned from use. Non-halogenated chemistries like red phosphorus may be limited in use in South Korea due to the potential for PH₃ formation when red phosphorus is exposed to humidity (which can be avoided by encapsulation of the red phosphorus).

      1.3.9 Australia

      In July of 2020, Australia introduced a sweeping new regulation for chemicals called the Australian Industrial Chemicals Introduction Scheme (AICIS) [59]. This law looks at all chemicals imported into Australia, as well as those created/used domestically, and covers applications that use those chemicals as well. There is an extensive chemical inventory to see what is known about a particular chemical (and where there are gaps) in a searchable database, and a list of those chemicals which are banned/restricted from use. The Australian law looks to international law as a basis for chemical bans, including chemicals found on the Stockholm Convention of Persistent Organic Pollutants, which includes HBCD, BDPEs, and some perbrominated/perchlorinated aromatic compounds. Tris(2,3-dibromopropyl)phosphate is also subject to regulation due to its negative PBT profile. As of 2020, no other non-halogenated flame retardants are on the regulated list with Australia.

1.4 Fire Safety and Non-Fire Safety Issues Requiring Non-Halogenated Flame Retardants

Depending upon the nature of a fire risk scenario and the codes/standards involved in regulating and testing materials with that particular scenario, there are cases where halogenated flame retardants cannot meet the fire safety requirements. These cases may result in non-halogenated FRs being favored for fire safety use. Typically, fire requirements around smoke and corrosive gas release limit the use of halogenated flame retardants. Smoke release may be limited in some compartment fires as the smoke may block visibility of exit signs or just visibility in general. Many halogenated flame retardants produce high levels of smoke upon burning since the halogenated flame retardants inhibit vapor phase combustion, thus leading to higher levels of smoke release [60–62]. Additionally, halogenated flame retardants often release corrosive gases during combustion (namely HBr and HCl), which can cause significant damage to electronics and electrical systems. Locations holding large numbers of computer servers, electronic data storage, and power switching systems typically have requirements against corrosive gases, and small compartments with sensitive electronics (aviation, maritime, aerospace) are likely to have similar requirements that limit or prevent the release of corrosive gases in a fire event. This can be compounded by heating, ventilation, and air conditioning (HVAC) systems that feed air into rooms holding these items, such that components in the ductwork or feeding air to the HVAC systems must also be non-halogenated to meet the corrosive gas requirement. Computer chip fabrication facilities also have corrosive gas emission requirements which often require the furniture, cabinetry, and items in the room to also be non-halogenated, or at least compliant by releasing little to not corrosive gases during a fire event [63]. Finally, there are some very strict combustion emission requirements for vehicles in extreme environments that have sealed atmospheres (submarines, spacecraft), and for that reason, corrosive gases are excluded with an emphasis on very low flammability first, and emissions second [64, 65].

Along with fire safety issues affecting the selection/de-selection of particular flame retardants, there are several non-fire safety issues that must be considered as well. Some of this was discussed in the previous section where specific chemicals are regulated, but it is worthwhile to review this again, as well as share some of the other requirements not specifically covered in chemical bans and chemical regulation. As mentioned previously, there are regulations which de-select halogenated flame retardants for environmental reasons, namely the WEEE and RoHS requirements covering electrical and electronic equipment. There are also voluntary labeling requirements which if met, allow additional branding of items to suggest that it has a better environmental profile than items that do not have this label. Examples of this include “ecolabels” like Blue Angel [66], European Union Ecolabel [67], Nordic Swan [68], Green Seal [69], Global GreenTag [70], and other relevant labels. These other labels may have a variety of non-fire related requirements which may de-select certain flame retardant chemicals. Recycling requirements and how a flame retardant chemical interacts with the recycling process (regrind & remelt, chemical depolymerization, waste-to-energy, etc.) may also prefer a particular flame retardant chemistry. Finally, there are issues with customer perception that will need to be addressed. For all the reasons mentioned above that are driving halogenated chemicals out of use where selected halogenated chemicals have negative PBT profiles, customers may demand non-halogenated even if the halogenated flame retardant can be made in such a way to have a positive PBT profile. The phrase “the customer is always right” is particularly true here if the customer is asking for non-halogenated flame retardant technology, even if it may be more expensive or the balance of properties in the final product is not as good as that possible with halogenated FRs. The same negative PBT data about СКАЧАТЬ