Flame Retardant Testing

1. Introduction to Flame Retardants

Flame retardants are functional additives that impart flame resistance to flammable polymers. Their advantages include low dosage, high flame retardant efficiency, and broad applicability. They are widely used in plastic modification and textile flame retardant finishing, with brominated and phosphorus-based flame retardants being the most commonly used. Flame retardants are toxic and potentially carcinogenic, are not easily degradable in the environment, and tend to accumulate in living organisms.

There are various types of flame retardants, categorized by application method into additive flame retardants and reactive flame retardants. Additive flame retardants are incorporated into polymers through mechanical mixing to impart flame retardancy. Currently, additive flame retardants mainly include organic and inorganic flame retardants, halogen-based flame retardants (organic chlorides and organic bromides), and non-halogen types. Organic flame retardants are represented by brominated, phosphorus-nitrogen, nitrogen-based, red phosphorus, and their compounds. Inorganic types mainly include antimony trioxide, magnesium hydroxide, aluminum hydroxide, silicon-based flame retardant systems, etc. Reactive flame retardants participate as monomers in polymerization reactions, thereby making the polymer itself contain flame retardant components. Their advantage is that they have less impact on the performance of polymer materials and provide durable flame retardancy.

1、Related Regulations

1. Flame Retardants of Concern in the Stockholm Convention

In May 2001, the international community adopted the Stockholm Convention on Persistent Organic Pollutants to gradually eliminate persistent organic pollutants (POPs) globally;

1) Persistent Organic Pollutants: Difficult to degrade, highly toxic, capable of long-range transport;

2) Flame retardants such as polybrominated biphenyls (PBBs), polybrominated diphenyl ethers (PBDEs), short-chain chlorinated paraffins (SCCPs), and hexabromocyclododecane (HBCDD) are listed in the Convention as POPs to be eliminated. Parties to the Convention are obligated to fulfill the objectives set forth by the Convention.

2. EU Regulations on Flame Retardants

1) EU Persistent Organic Pollutants Regulation, established based on the Stockholm Convention;

2) EU RoHS Directive: Targets electrical and electronic products; restricted flame retardants include polybrominated biphenyls (PBBs) and polybrominated diphenyl ethers (PBDEs);

3) EU REACH Regulation: Flame retardants included in the SVHC list and Annex XVII include tris(2-chloroethyl) phosphate (TCEP), tricresyl phosphate (TCP), tris(2,3-dibromopropyl) phosphate (TDBPP), tris(aziridinyl)phosphine oxide (TEPA), monomethyl dibromodiphenyl methane, etc.;

4) The EU ErP Directive proposes to ban the use of halogenated flame retardants in the enclosures and stands of electronic displays.

3. US Regulations on Flame Retardants

1) The EPA monitors persistent organic pollutants at the federal level;

2) Various states in the US have introduced bans or restrictions on flame retardants in consumer products. The flame retardants involved include octabromodiphenyl ether (OctaBDE), decabromodiphenyl ether (DecaBDE), tris(2-chloroethyl) phosphate (TCEP), tris(1,3-dichloro-2-propyl) phosphate (TDCPP), short-chain chlorinated paraffins (SCCPs), hexabromocyclododecane (HBCDD), 2-ethylhexyl tetrabromobenzoate (TBB), tetrabromobisphenol A (TBBPA), bis(2-ethylhexyl) tetrabromophthalate (TBPH), etc.

3. Testing Methods

Common testing methods for textile flame retardancy include the vertical flame test, 45° flame test, horizontal flame test, cigarette and small flame ignition tests, etc.

Overview of Flame Retardancy Test Methods for Textiles in China