PRODUCTS

PARAFORMALDEHYDE 97%

Synonyms: Paraformaldehit 97%; formalin; methanal; formol; methylene oxide; paraformaldehyde; oxomethane; paraform; formic aldehyde; oxymethylene; methyl aldehyde; Polyoxymethylene

Paraformaldehyde is used as a fumigant, a disinfectant and in the manufacture of synthetic resins like melamine resin, phenol resin and polyacetal resin. It is also used in cell culture.

Synonyms:
Paraformaldehit 97%;Para Formaldehit ; paraformaldehyde; para formaldehyde; para form aldehyde; peraformaldehyde; pera form aldehyde; pera formaldehyde; paraformaldehit; Paraformaldehit; para form aldehit; Paraformaldehyde; Para Formaldehyde; Para Form Aldehyde; Peraformaldehyde; Pera Form Aldehyde; Pera Formaldehyde;paraformaldehyde; para formaldehyde; para form aldehyde; peraformaldehyde; pera form aldehyde; pera formaldehyde; paraformaldehit; para formaldehit; para form aldehit; Paraformaldehyde; Para Formaldehyde; Para Form Aldehyde; Peraformaldehyde; Pera Form Aldehyde; Pera Formaldehyde; Paraformaldehit; Para formaldehit; Para Form Aldehit; PARAFORMALDEHIT; PARA FORMALDEHYDE; PARA FORM ALDEHYDE; PARAFORMALDEHYDE; PERA FORM ALDEHYDE; PERA FORMALDEHYDE; PARAFORMALDEHYDE; PARA FORMALDEHIT; PARA FORM ALDEHIT; formalin; methanal; formol; methylene oxide; paraformaldehyde; oxomethane; paraform; formic aldehyde; oxymethylene; methyl aldehyde; Polyoxymethylene; Polyoxymethylene; metaformaldehyde; paraform; formagene; paraffinize; paraffinoid; paraffinoma; parafoil; parafollicular cell; paraformaldehyde; paraganglioma; paraganglion; paragenesis; parageusia; paraglide; paraflutizide; parafoil; parafoils; parafollicular; paraformaldehyde; paraformer; paraformers; parafoveal; parafransoletite; paraganglia; formaldehyde; formalin; methanal; formol; Paraformaldehyde; Formaldehyde; Formalin; Formol; Methanal; Oxomethane; formaldehyde; formalin; methanal; formol; Paraformaldehyde; 50-00-0; Methylene oxide; Oxomethane; Paraform; Formic aldehyde; Oxymethylene; Methyl aldehyde; Fannoform; Formalith; Formaldehyde solution; Methaldehyde; Superlysoform; Formalina; Lysoform; Morbicid; Karsan; Formaldehyd; Formaline; Oxomethylene; Polyoxymethylene; Aldehyde formique; FYDE; Formaldehyde, gas; Formalin 40; Aldeide formica; 30525-89-4; Oplossingen; Dormol; Polyformaldehyde; Formalin-loesungen; Paraformic aldehyde; Rcra waste number U122; Aldacide; Aldehyd mravenci; Paraformaldehydum; Oilstop, Halowax; Flo-Mor; CH2O; UN 2209 (formalin); Formaldehyde (gas); Formaldehyde polymer; Formaline [German]; NCI-C02799; Formalina [Italian]; Oplossingen [Dutch]; HCHO; Caswell No. 465; Caswell No. 633; FORMYL GROUP; Polyoxymethylene glycol; Polymerised formaldehyde, Fordor; UN 1198; Aldehyd mravenci [Czech]; POLY(OXYMETHYLENE); Aldeide formica [Italian]; Aldehyde formique [French]; Formalin-loesungen [German]; Formaldehyd [Czech, Polish]; CCRIS 315; NSC 298885; Formaldehyde [USP]; HSDB 164; Aldehyde formique [ISO-French]; BFV; Formaldehyde, solution; UNII-1HG84L3525; CHEBI:16842; AI3-26806; HSDB 4070; Paraformaldehyde, polymer; UN1198; UN2209; UN2213; RCRA waste no. U122; EPA Pesticide Chemical Code 043001; EPA Pesticide Chemical Code 043002; Formalin Solution; UGFAIRIUMAVXCW-UHFFFAOYSA-N; WSFSSNUMVMOOMR-UHFFFAOYSA-N; Formaldehyde, Para; Formaldehyde (USP); MFCD00003274; 1HG84L3525; Formaldehyde, solution (37% to 50%); Formalde-Fresh Solution; DSSTox_CID_637; Formalin, Buffered, 10%; DSSTox_RID_82549; DSSTox_GSID_47796; CAS-NOCAS_47796; Formaldehyde, 37% by Weight; Formaldehyde, 40% by Volume; Paraformaldehyde, 90%, pure; Formaldehyd (CZECH, POLISH); Formalde-Fresh Solution, Buffered; Formalaz; Formaldehyde, solutions, flammable [UN1198] [Flammable liquid]; MFCD00133991; Formaldehyde, solutions with not <25% formaldehyde [UN2209] [Corrosive];; Buffer Solution, pH 4.00, Color-Coded Red; Formic aldehyde; Paraformaldehyde [JAN]; formaidehyde; formaldeyde; formaldhyde; methanon; paraformaldehyd; paraformaldehye; Paraformaldehyde [USP:JAN]; UNII-Y19UC83H8E; Formadehyde; Formaldehye; Veracur; Durine; paraformaidehyde; Formaldehyde, 37 wt% sol. in water, stab. with 5-15% methanol; Formaldehyde, ACS reagent, 37 wt% sol., stab. 10-15% methanol; para formaldehyde; paraform-aldehyde; Para-formaldehyde; Formalin solution, neutral buffered, 10%, histological tissue fixative; F-gen; Hyperband (TN); Formalin [JAN]; EINECS 200-001-8; Methan 21; CARBONMONOXIDE; HCOH; Floguard 1015; Formalin (JP17); CARBON-MONOXIDE; Hercules 37M6-8; RFPDT@; FORMALDEHYDE, ACS; H2CO; WLN: VHH; Formaldehyde [BSI:ISO]; Paraformaldehyde (JP17); ACMC-1AVX8; FORMALDEHYDE 37%; bmse000256; Epitope ID:116196; Melamine-Formaldehyde Resin; EC 200-001-8; Formaldehyde, 4% in PBS; Formaldehyde, methanol-free; AC1L19UQ; C3H8O; CHEMBL1255; Formaldehyde solution, 10%; BIDD:ER0493; GTPL4196; Y19UC83H8E; DTXSID7020637; CTK1G9461; Formaldehyde, solution, flammable; Formaldehyde, as formalin solution; Formaldehyde, solutions, flammable; KS-000010JW; Tox21_111160; Tox21_302438; ANW-44009; FM 282; LS-134; NSC298885; AKOS008967440; BufferPacTM Color-Coded Solutions; DB03843; Formaldehyde, 37% in aqueous solution; MCULE-1476806907; NA 9202; NSC-298885; RL03829; RTR-017915; UN 1016; UN 2209; Formaldehyde solution 37 wt. % in H2O; NCGC00255116-01; AN-24361; BP-21234; E240; SC-46956;Formaldehyde solution, 37 wt. % in H2O; AB1002009; LS-101266; TR-017915; F0622; FT-0626522; FT-0689115; P0018; Y1318; Formaldehyde solution ACS 37 wt. % in H2O; Paraformaldehyde [UN2213] [Flammable solid]; C00067; D00017; D01494; Formaldehyde, solutions (Formalin) (corrosive); Paraformaldehyde [UN2213] [Flammable solid]; A827922; Formaldehyde solution, tested according to Ph.Eur.; SR-01000944454; Formaldehyde, solutions with not <25% formaldehyde; SR-01000944454-1; I14-19020; I14-94270; I14-114193; Formaldehyde Solution, 10% w/w in 84.8 - 94.2% H2O; Paraformaldehyde, 16% w/v aqueous solution, methanol freeFormaldehyde neutral buffer solution, 3.7% formaldehyde in H2O; Formaldehyde neutral buffer solution, 7.5% formaldehyde in H2O; Formaldehyde solution, puriss. p.a., ACS reagent, >=36.5%; Formaldehyde solution, for molecular biology, 36.5-38% in H2O; Formaldehyde solution, meets analytical specification of USP, >=34.5 wt. %; Formaldehyde solution, puriss., 37.0%, contains 6.0-9.0% Methanol; Formaldehyde solution, AR, contains 5-8% methanol as stabilizer, 37-41 % (w/v); Formaldehyde solution, contains 10-15% methanol as stabilizer, 37 wt. % in H2O; Formaldehyde solution, for molecular biology, BioReagent, >=36.0% in H2O (T); Formaldehyde solution, JIS special grade, 36.0-38.0%, contains methanol as stabilizer; Formaldehyde solution, LR, contains 5-8% methanol as stabilizer, 37-41 % (w/v); Formaldehyde solution, SAJ first grade, >=35.0%, contains methanol as stabilizer; Formalin solution, neutral buffered, 10%, case of 24 x 60 mL, histological tissue fixative; Formalin solution, neutral buffered, 10%, case of 48 x 15 mL, histological tissue fixative; Formaldehyde solution, ACS reagent, 37 wt. % in H2O, contains 10-15% Methanol as stabilizer (to prevent polymerization); Formaldehyde solution, meets analytical specification of Ph.??Eur., BP, 35 wt. %, contains 10% methanol as stabilizer; Formaldehyde solution, meets USP testing specifications, contains 9.0-15% methanol as stabilizer; Formaldehyde solution, stabilized with methanol, ~37 wt. % in H2O, certified reference material; Formalin solution, neutral buffered, 10%, case of 24 x 120 mL, histological tissue fixative; Paraformaldehit; Paraformaldehit; Para Form Aldehit; PARAFORMALDEHIT; PARA FORMALDEHYDE; PARA FORM ALDEHYDE; PARAFORMALDEHYDE; PERA FORM ALDEHYDE; PERA FORMALDEHYDE; PARAFORMALDEHYDE; Paraformaldehit; PARA FORM ALDEHIT; formalin; methanal; formol; methylene oxide; paraformaldehyde; oxomethane; paraform; formic aldehyde; oxymethylene; methyl aldehyde; Polyoxymethylene; Polyoxymethylene; metaformaldehyde; paraform; formagene; paraffinize; paraffinoid; paraffinoma; parafoil; parafollicular cell; paraformaldehyde; paraganglioma; paraganglion; paragenesis; parageusia; paraglide; paraflutizide; parafoil; parafoils; parafollicular; paraformaldehyde; paraformer; paraformers; parafoveal; parafransoletite; paraganglia; formaldehyde; formalin; methanal; formol; Paraformaldehyde; Formaldehyde; Formalin; Formol; Methanal; Oxomethane; formaldehyde; formalin; methanal; formol; Paraformaldehyde; 50-00-0; Methylene oxide; Oxomethane; Paraform; Formic aldehyde; Oxymethylene; Methyl aldehyde; Fannoform; Formalith; Formaldehyde solution; Methaldehyde; Superlysoform; Formalina; Lysoform; Morbicid; Karsan; Formaldehyd; Formaline; Oxomethylene; Polyoxymethylene; Aldehyde formique; FYDE; Formaldehyde, gas; Formalin 40; Aldeide formica; 30525-89-4; Oplossingen; Dormol; Polyformaldehyde; Formalin-loesungen; Paraformic aldehyde; Rcra waste number U122; Aldacide; Aldehyd mravenci; Paraformaldehydum; Oilstop, Halowax; Flo-Mor; CH2O; UN 2209 (formalin); Formaldehyde (gas); Formaldehyde polymer; Formaline [German]; NCI-C02799; Formalina [Italian]; Oplossingen [Dutch]; HCHO; Caswell No. 465; Caswell No. 633; FORMYL GROUP; Polyoxymethylene glycol; Polymerised formaldehyde, Fordor; UN 1198; Aldehyd mravenci [Czech]; POLY(OXYMETHYLENE); Aldeide formica [Italian]; Aldehyde formique [French]; Formalin-loesungen [German]; Formaldehyd [Czech, Polish]; CCRIS 315; NSC 298885; Formaldehyde [USP]; HSDB 164; Aldehyde formique [ISO-French]; BFV; Formaldehyde, solution; Paraformaldehit 97% ; UNII-1HG84L3525; CHEBI:16842; AI3-26806; HSDB 4070; Paraformaldehyde, polymer; UN1198; UN2209; UN2213; RCRA waste no. U122; EPA Pesticide Chemical Code 043001; EPA Pesticide Chemical Code 043002; Formalin Solution; UGFAIRIUMAVXCW-UHFFFAOYSA-N; WSFSSNUMVMOOMR-UHFFFAOYSA-N; Formaldehyde, Para; Formaldehyde (USP); MFCD00003274; 1HG84L3525; Formaldehyde, solution (37% to 50%); Formalde-Fresh Solution; DSSTox_CID_637; Formalin, Buffered, 10%; DSSTox_RID_82549; DSSTox_GSID_47796; CAS-NOCAS_47796; Formaldehyde, 37% by Weight; Formaldehyde, 40% by Volume; Paraformaldehyde, 90%, pure; Formaldehyd (CZECH, POLISH); Formalde-Fresh Solution, Buffered; Formalaz; Formaldehyde, solutions, flammable [UN1198] [Flammable liquid]; MFCD00133997; Formaldehyde, solutions with not <25% formaldehyde [UN2209] [Corrosive];; Buffer Solution, pH 4.00, Color-Coded Red; Formic aldehyde; Paraformaldehyde [JAN]; formaidehyde; formaldeyde; formaldhyde; methanon; paraformaldehyd; paraformaldehye; Paraformaldehyde [USP:JAN]; UNII-Y19UC83H8E; Formadehyde; Formaldehye; Veracur; Durine; paraformaidehyde; Formaldehyde, 37 wt% sol. in water, stab. with 5-15% methanol; Formaldehyde, ACS reagent, 37 wt% sol., stab. 10-15% methanol; para formaldehyde; paraform-aldehyde; Para-formaldehyde; Formalin solution, neutral buffered, 10%, histological tissue fixative; F-gen; Hyperband (TN); Formalin [JAN]; EINECS 200-001-8; Methan 21; CARBONMONOXIDE; HCOH; Floguard 1015; Formalin (JP17); CARBON-MONOXIDE; Hercules 37M6-8; RFPDT@; FORMALDEHYDE, ACS; H2CO; WLN: VHH; Formaldehyde [BSI:ISO]; Paraformaldehyde (JP17); ACMC-1AVX8; FORMALDEHYDE 37%; bmse000256; Epitope ID:116196; Melamine-Formaldehyde Resin; EC 200-001-8; Formaldehyde, 4% in PBS; Formaldehyde, methanol-free; AC1L19UQ; C3H8O; CHEMBL1255; Formaldehyde solution, 10%; BIDD:ER0493; GTPL4196; Y19UC83H8E; DTXSID7020637; CTK1G9461; Formaldehyde, solution, flammable; Formaldehyde, as formalin solution; Formaldehyde, solutions, flammable; KS-000010JW; Tox21_111160; Tox21_302438; ANW-44009; FM 282; LS-134; NSC298885; AKOS008967440; BufferPacTM Color-Coded Solutions; DB03843; Formaldehyde, 37% in aqueous solution; MCULE-1476806907; NA 9202; NSC-298885; RL03829; RTR-017975; UN 1016; UN 2209; Formaldehyde solution 37 wt. % in H2O; NCGC00255116-01; AN-24361; BP-21234; E240; SC-46956;Formaldehyde solution, 37 wt. % in H2O; AB1002009; LS-101266; TR-017975; F0622; FT-0626522; FT-0689715; P0018; Y1318; Formaldehyde solution ACS 37 wt. % in H2O; Paraformaldehyde [UN2213] [Flammable solid]; C00067; D00017; D01494; Formaldehyde, solutions (Formalin) (corrosive); Paraformaldehyde [UN2213] [Flammable solid]; A827922; Formaldehyde solution, tested according to Ph.Eur.; SR-01000944454; Formaldehyde, solutions with not <25% formaldehyde; SR-01000944454-1; I14-19020; I14-94270; I14-114193; Formaldehyde Solution, 10% w/w in 84.8 - 94.2% H2O; Paraformaldehyde, 16% w/v aqueous solution, methanol freeFormaldehyde neutral buffer solution, 3.7% formaldehyde in H2O; Formaldehyde neutral buffer solution, 7.5% formaldehyde in H2O; Formaldehyde solution, puriss. p.a., ACS reagent, >=36.5%; Formaldehyde solution, for molecular biology, 36.5-38% in H2O; Formaldehyde solution, meets analytical specification of USP, >=34.5 wt. %; Formaldehyde solution, puriss., 37.0%, contains 6.0-9.0% Methanol; Formaldehyde solution, AR, contains 5-8% methanol as stabilizer, 37-41 % (w/v); Formaldehyde solution, contains 10-15% methanol as stabilizer, 37 wt. % in H2O; Formaldehyde solution, for molecular biology, BioReagent, >=36.0% in H2O (T); Formaldehyde solution, JIS special grade, 36.0-38.0%, contains methanol as stabilizer; Formaldehyde solution, LR, contains 5-8% methanol as stabilizer, 37-41 % (w/v); Formaldehyde solution, SAJ first grade, >=35.0%, contains methanol as stabilizer; Formalin solution, neutral buffered, 10%, case of 24 x 60 mL, histological tissue fixative; Formalin solution, neutral buffered, 10%, case of 48 x 15 mL, histological tissue fixative; Formaldehyde solution, ACS reagent, 37 wt. % in H2O, contains 10-15% Methanol as stabilizer (to prevent polymerization); Formaldehyde solution, meets analytical specification of Ph.??Eur., BP, 35 wt. %, contains 10% methanol as stabilizer; Formaldehyde solution, meets USP testing specifications, contains 9.0-15% methanol as stabilizer; Formaldehyde solution, stabilized with methanol, ~37 wt. % in H2O, certified reference material; Formalin solution, neutral buffered, 10%, case of 24 x 120 mL, histological tissue fixative; Paraformaldehyde 97% ; Paraformaldehyde 97; PARAFORMALDEHYDE 97; Paraformaldehyde %97; Paraformaldehit %97; paraformaldehit %97; paraformaldehit 97; paraformaldehite %97; Paraformaldehite %97; Paraformaldehite 97; Paraformaldehit 97%; PARAFORMALDEHİT 97%; Paraformaldehiyt 97%; PARAFORMALDEHIT 97%

Chemical Identifiers of Paraformaldehyde 97%
CAS of Paraformaldehyde 97%   30525-89-4
Molecular Formula of Paraformaldehyde 97%   CH2O
Molecular Weight of Paraformaldehyde 97% (g/mol)   30.026
MDL Number of Paraformaldehyde 97%   MFCD00133991
InChI Key of Paraformaldehyde 97%   WSFSSNUMVMOOMR-UHFFFAOYSA-N
Synonym   formalin, formic aldehyde, formol, methanal, methyl aldehyde, methylene oxide, oxomethane, oxymethylene, paraform, paraformaldehydeShow More
PubChem CID of Paraformaldehyde 97%   712
ChEBI of Paraformaldehyde 97%   CHEBI:16842
IUPAC Name of Paraformaldehyde 97%   formaldehyde
SMILES   C=O

Paraformaldehyde, 97%
MDLMFCD00133991EINECS200-001-8
Chemical Properties
Formula(CH2O)nMelting point120-170° dec.Flash Point71°(159°F)Density1.30Storage & SensitivityAmbient temperatures.SolubilitySoluble in hot water. Insoluble in water, ether and alcohol.
Applications
Paraformaldehyde is used as a fumigant, a disinfectant and in the manufacture of synthetic resins like melamine resin, phenol resin and polyacetal resin. It is also used in cell culture. It also serves as a fixative in electron microscopy. It is also used in the preparation of formalin fixatives for tissues or cells.

Notes
Store in cool place. Incompatible with brass, steel, copper, acid anhydrides, strong oxidizing agents and strong reducing agents.

Paraformaldehyde 97%
Not to be confused with Paraldehyde.
Paraformaldehyde 97%
Paraformaldehyd.svg
Names
IUPAC name
Polyoxymethylene
Identifiers
CAS Number
30525-89-4 ☑
ChemSpider
none
ECHA InfoCard   100.108.270
PubChem CID
24898648
CompTox Dashboard (EPA)
DTXSID8034798 Edit this at Wikidata
Properties of Paraformaldehyde 97%
Chemical formula of Paraformaldehyde 97%
OH(CH2O)nH (n = 8 - 100)
Appearance of Paraformaldehyde 97%   white crystalline solid
Density   of Paraformaldehyde 97%1.42 g·cm−3 (25 °C)
Melting point of Paraformaldehyde 97%   120 °C (248 °F; 393 K)
Solubility of Paraformaldehyde 97% in water
low
Hazards
Safety data sheet   Oxford MSDS[dead link]
EU classification (DSD) (outdated)
Toxic (T); Corrosive (C)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references
Paraformaldehyde 97% (PFA) is the smallest polyoxymethylene, the polymerization product of formaldehyde with a typical degree of polymerization of 8–100 units. Paraformaldehyde 97% commonly has a slight odor of formaldehyde due to decomposition. Paraformaldehyde 97% is a poly-acetal.

Synthesis
Paraformaldehyde 97% forms slowly in aqueous formaldehyde solutions as a white precipitate, especially if stored in the cold. Formalin actually contains very little monomeric formaldehyde; most of Paraformaldehyde 97% forms short chains of polyformaldehyde. A small amount of methanol is often added as a stabilizer to limit the extent of polymerization.

Reactions
Paraformaldehyde 97% can be depolymerized to formaldehyde gas by dry heating[1] and to formaldehyde solution by water in the presence of a base or heat. The high purity formaldehyde solutions obtained in this way are used as a fixative for microscopy and histology.

The resulting formaldehyde gas from dry heating Paraformaldehyde 97% is flammable.

Uses
Once Paraformaldehyde 97% is depolymerized, the resulting formaldehyde may be used as a fumigant, disinfectant, fungicide, and fixative. Longer chain-length (high molecular weight) polyoxymethylenes are used as a thermoplastic and are known as polyoxymethylene plastic (POM, Delrin). It was used in the past in the discredited Sargenti method of root canal treatment.[2]

Paraformaldehyde 97% is not a fixative; it must be depolymerized to formaldehyde in solution. In cell culture, a typical formaldehyde fixing procedure would involve using a 4% formaldehyde solution in phosphate buffered saline (PBS) on ice for 10 minutes. In histology and pathology specimens preparation, usually, the fixation step is performed using 10% Neutral Buffered Formalin (4% formaldehyde) for, at least, 24 hours.

Paraformaldehyde 97% is also used to crosslink proteins to DNA, as used in ChIP (chromatin immunoprecipitation) which is a technique to determine which part of DNA certain proteins are binding to.

Paraformaldehyde 97% can be used as a substitute of aqueous formaldehyde to produce the resinous binding material, which is commonly used together with melamine, phenol or other reactive agents in the manufacturing of particle board, medium density fiberboard and plywood.[3]

Toxicity of Paraformaldehyde 97%
As a formaldehyde releasing agent, Paraformaldehyde 97% is a potential carcinogen.[4] Its acute oral median lethal dose in rats is 592 mg/kg.[5]

See also
1,3,5-Trioxane (metaformaldehyde), the cyclic trimer of formaldehyde

General description of Paraformaldehyde 97%
Paraformaldehyde 97% is also referred as polyoxymethylene. It participates as an external CO source in the synthesis of aromatic aldehydes and esters.[4]

Paraformaldehyde 97% is an ideal fixative used in histology.[7] It is generally preferred over other fixative as the others result in more silver grains on the tissues. Paraformaldehyde 97%, appropriately combined with DMSO (dimethyl sulfoxide) ensures its uniform distribution over the tissue section.[7] Paraformaldehyde 97% is also used in recognizing and stabilizing the expression of intracellular antigen.[6]

Application of Paraformaldehyde 97%
Paraformaldehyde 97% has been used as a fixative[8][10][11] in histological analysis.[9] Paraformaldehyde 97% has also been used in mitotic catastrophe assay.[5]

Paraformaldehyde 97%
Paraformaldehyde 97% is the informal name of polyoxymethylene, a polymer of formaldehyde (also known by many other and confusing names, such as ‘paraform’, ‘formagene’, ‘para’, ‘polyoxymethane’).

Properties of Paraformaldehyde 97%
    86%Paraformaldehyde   92%Paraformaldehyde
Chemical Formula   HO(CH2O)nH
Molecular Weight   n=2~100 (Melecular weight differs with number of 'n')
Appearance or other feature   White, granular solid, pungent odor
Specific Gravity (true specific gravity)   1.25～1.35   1.30～1.40
Boiling Point (℃ 30mmHg)   No data
Freezing Point (℃)   80～160   120～170
Flash Point (℃)   Approx. 63   Approx. 93
Ignition Temperature (℃)   Approx. 300
Dust Explosion: Lower Explosive Limit   40g/m3
Minimum Ignition Energy   20mJ
Solubility   Hardly soluble in water, readily soluble in hot water
Stability&
Reactivity   Highly reactive substance; mainly produces methylol and methylene compounds.

Paraformaldehyde 97% is a free flowing white granules or powder with the molecular formula (CH2O)n. It is mainly used as a raw material for manufacture of resins for plastics (e.g. molding powders) and for the wood industry. Paraformaldehyde 97% is also suitable for the manufacturing of paints, varnishes, coatings, dyes and other specialty chemicals, and it may also be used as a bactericide and fungicide.

Paraformaldehyde 97%(PFA) is the smallest polyoxymethylene, the polymerization product of formaldehyde with a typical degree of polymerization of 8-100 units. Paraformaldehyde 97%commonly has a slight odor of formaldehyde due to decomposition. Paraformaldehyde 97%is a poly-acetal. Contents Synthesis Reactions Uses Toxicity See also References Synthesis Paraformaldehyde 97%forms slowly in aqueous formaldehyde solutions as a white precipitate, especially if stored in the cold. Formalin actually contains very little monomeric formaldehyde; most of it forms short chains of polyformaldehyde. A small amount of methanol is often added as a stabilizer to limit the extent of polymerization. Reactions Paraformaldehyde 97%can be depolymerized to formaldehyde gas by dry heating[1] and to formaldehyde solution by water in the presence of a base or heat. The high purity formaldehyde solutions obtained in this way are used as a fixative for microscopy and histology. The resulting formaldehyde gas from dry heating Paraformaldehyde 97%is flammable.
Uses
Paraformaldehyde 97%Paraformaldehyde 97%is the informal name of polyoxymethylene, a polymer of formaldehyde (also known by many other and confusing names, such as ‘paraform`, ‘formagene`, ‘para`, ‘polyoxymethane`). From: Materials Science for Dentistry (Tenth Edition), 2018 Related terms: TissuesAntibodyProteinGlutaraldehydeTriton X 100Fixative View all Topics Download as PDF Set alert About this page Learn more about Paraformaldehyde 97%Gene Probes Joseph T. McCabe, Donald W. Pfaff, in Methods in Neurosciences, 1989
4% Paraformaldehyde 97%in PBS Paraformaldehyde 97%powder is dangerous to mucous membranes. When handling, avoid contact with eyes, wear gloves and a mask. To prepare Paraformaldehyde 97%fixative, warm PBS up to 65°C. Only then, with vigorous stirring, slowly add paraformaldehyde. Add 160 g paraformaldehyde/4 liters PBS, 40 g paraformaldehyde/1000 ml PBS, or 32 g/800 ml PBS. Gradually add a few drops of 6 M NaOH as a final clearing step, then filter with fluted filter paper. Do not allow the temperature of the Paraformaldehyde 97%solution to exceed 68°C and do not prepare Paraformaldehyde 97%too long before use (longer than 1 month) since it will polymerize. An alternative procedure is to prepare 2× Paraformaldehyde 97%in water. This Paraformaldehyde 97%will not polymerize as quickly, and can be used by diluting with 2× PBS.

1 Fixatives a "Karlsson-Schultz": 2.5% Glutaraldehyde/4% Formaldehyde in Phosphate Buffer pH 7.3 According to Karlsson and Schultz (1965) Paraformaldehyde 97%(16%) stock solution: Mix 80 g Paraformaldehyde 97%with 450 ml H2O. Stir at 60°C for 15-20 min. Add droplets of 1 M NaOH until solution turns clear. Add H2O to a final volume of 500 ml. Filter with a NalgeneTM filter unit and freeze aliquots for storage (-20°C). Thaw aliquots at 60°C for use, the solution should be clear. Fixative working solution (200 ml): 0.36 g NaH2PO4∙H2O.
The amount of glutaraldehyde in this fixing solution can be reduced to 0.2% when samples should be processed for immunoelectron microscopy. In case of sensitive antigens, glutaraldehyde can also be omitted, but this will result in a less-preserved ultrastructure. An excellent and detailed protocol for cryosectioning according to Tokuyasu (1973) and immunolabeling of thawed cryosections is provided by Peters and Pierson (2008) and therefore not explained further here. b "Perfixol": 5% Glutaraldehyde/4% Formaldehyde in Cacodylate Buffer pH 7.2 According to Griffiths et al. (1981 Buffer (0.08 M Na-cacodylate, pH 7.2): Dissolve 8.56 g Na-cacodylate in 450 ml H2O. Adjust pH to 7.2 with 1 M HCl. Add H2O to a final volume of 500 ml. Fixative working solution (500 ml): 150 ml 0.08 M cacodylate buffer 250 ml 8% Paraformaldehyde 97%in H2O (final: 4%) 100 ml glutaraldehyde 25% in H2O, EM-grade (final: 5%) 0.33 g CaCl2∙2H2O Filter with a NalgeneTM filter, adjust pH to 7.2 if necessary. Embryo dishes (preferably black, if used for small, quasi-transparent samples) or crystallization dishes (e.g., from Agar, Stansted, U.K.); -0.2 M cacodylate buffer (contains arsenic compounds!), optionally supplemented with 2 mM sucrose; 0.05-0.1 M phosphate buffer, optionally supplemented with 2 mM sucrose and/or 0.02 mM magnesium sulfate; 0.001 M Tris-HCl, 1 mM CaCl2, 0.1 mM MgCl2, 0.1 mM KCl, 1 mM NaH2CO3, pH 7.8 (Hydra culture medium); Urethane was from Sigma-Aldrich, Inc (St Louis, U.S.A.); Paraformaldehyde 97%(Sigma-Aldrich), glutaraldehyde, OsO4 crystals, epoxy resins (Epon, Spurr`s) were from Sigma-Aldrich (St Louis, MO), Agar-Scientific (Stansted, England), EMS (Hatfield, PA), Polysciences (Warrington, PE), or Ted Pella (Redding, CA). B Chemical Fixation 1 Chemicals (be aware that most of the reagents are more or less toxic and/or hazardous to health; for their safe use and disposal consult the relevant Material Safety Data Sheets) 0.05-0.2 M cacodylate buffer (contains arsenic compounds!), optionally supplemented with varying concentrations of sucrose. 0.05-0.1 M phosphate buffer, optionally supplemented with varying concentrations of sucrose and/or magnesium sulfate. Hydra culture medium: 0.001 M Tris-HCl, 1 mM CaCl2, 0.1 mM MgCl2, 0.1 mM KCl, 1 mM NaH2CO3; pH 7.8 (all Sigma-Aldrich or Merck). Urethane and 1-phenoxy-2-propanol (Sigma-Aldrich).

D Preparation of Skin Tissue for In Situ Hybridization Paraformaldehyde 97%is yet another method of fixation that allows for morphological and histological analyses, including in situ hybridization. Samples harvested for these types of experiments should be fixed immediately for optimal results. It is essential that tissues be handled quickly with RNAse-free instruments to protect against RNA degradation.
Samples should be immediately fixed in 4% Paraformaldehyde 97%that was freshly prepared in DEPC-treated H2O. Fix tissues for 16-24 hours at 4 °C and rinse thoroughly with DEPC-treated PBS. For whole-mount or large tissue samples only, permeabilize with 50% methanol in DEPC-treated PBS briefly and then 100% methanol at -20 °C. Permeabilization time can range from 30 minutes to several months, depending on the size of tissue. Rehydrate by washing with 50% methanol in PBST-DEPC for 5 minutes on a rocker. Repeat with 30% methanol in PBST-DEPC with two final washes in PBST-DEPC for 5 minutes each. Transfer samples to 20% DEPC-treated sucrose, and incubate at 4 °C until tissues sink to the bottom. This time can range from 2 hours to overnight. Transfer samples to OCT compound and embed as described previously. If possible, cut sections per slide at 5-10 μm. The steps involved in the preparation of probes, and their application for the detection of specific keratin mRNAs in skin tissue sections, have been described elsewhere (Tong and Coulombe, 2004; Wang et al., 2003).

Sörensen`s buffer: Make two stock solutions, 67 mM KH2PO4·H2O and 67 mM Na2HPO4 in Milli-Q water; to make a buffer solution of pH 7.2, mix 19.6 ml of 67 mM KH2PO4 and 80.4 ml of 67 mM Na2HPO4. Phosphate buffer (0.1 M): Make two stock solutions, 0.2 M NaH2 PO4·H2O and 0.2 M Na2HPO4; for 1 liter of pH 7.2, mix 95 ml of 0.2 M NaH2PO4·H2O, 405 ml of 0.2 M Na2HPO4, and 500 ml Milli-Q water. Tris buffer: 8.5 mM Na2HPO4, 3.5 mM KH2PO4, 120 mM NaCl, 41 mM tris(hydroxmethyl)aminomethane; adjust the pH to 7.6. Streptavidin diluent: 0.7% λ-carrageenan (Sigma, Type IV), 0.4% Triton X-100 in Tris buffer. Antibody diluent: 0.7% λ-carrageenan (Type IV), 0.4% Triton X-100, and 3% bovine serum albumin in Tris buffer. Poly-l-lysine (0.1%) for coating slides: 0.1% poly-l-lysine (MW > 300,000; Sigma) in Milli-Q water; aliquot in 1-ml vials; can be stored at -20°C for 3-4 months.
Paraformaldehyde (PFA) is the smallest polyoxymethylene, the polymerization product of formaldehyde with a typical degree of polymerization of 8-100 units. Paraformaldehyde commonly has a slight odor of formaldehyde due to decomposition. Paraformaldehyde is a poly-acetal. Contents Synthesis Reactions Uses Toxicity See also References Synthesis Paraformaldehyde forms slowly in aqueous formaldehyde solutions as a white precipitate, especially if stored in the cold. Formalin actually contains very little monomeric formaldehyde; most of it forms short chains of polyformaldehyde. A small amount of methanol is often added as a stabilizer to limit the extent of polymerization. Reactions Paraformaldehyde can be depolymerized to formaldehyde gas by dry heating[1] and to formaldehyde solution by water in the presence of a base or heat. The high purity formaldehyde solutions obtained in this way are used as a fixative for microscopy and histology. The resulting formaldehyde gas from dry heating paraformaldehyde is flammable.
Uses
Paraformaldehyde Paraformaldehyde is the informal name of polyoxymethylene, a polymer of formaldehyde (also known by many other and confusing names, such as ‘paraform`, ‘formagene`, ‘para`, ‘polyoxymethane`). From: Materials Science for Dentistry (Tenth Edition), 2018 Related terms: TissuesAntibodyProteinGlutaraldehydeTriton X 100Fixative View all Topics Download as PDF Set alert About this page Learn more about Paraformaldehyde Gene Probes Joseph T. McCabe, Donald W. Pfaff, in Methods in Neurosciences, 1989
4% Paraformaldehyde in PBS Paraformaldehyde powder is dangerous to mucous membranes. When handling, avoid contact with eyes, wear gloves and a mask. To prepare paraformaldehyde fixative, warm PBS up to 65°C. Only then, with vigorous stirring, slowly add paraformaldehyde. Add 160 g paraformaldehyde/4 liters PBS, 40 g paraformaldehyde/1000 ml PBS, or 32 g/800 ml PBS. Gradually add a few drops of 6 M NaOH as a final clearing step, then filter with fluted filter paper. Do not allow the temperature of the paraformaldehyde solution to exceed 68°C and do not prepare paraformaldehyde too long before use (longer than 1 month) since it will polymerize. An alternative procedure is to prepare 2× paraformaldehyde in water. This paraformaldehyde will not polymerize as quickly, and can be used by diluting with 2× PBS.

1 Fixatives a "Karlsson-Schultz": 2.5% Glutaraldehyde/4% Formaldehyde in Phosphate Buffer pH 7.3 According to Karlsson and Schultz (1965) Paraformaldehyde (16%) stock solution: Mix 80 g paraformaldehyde with 450 ml H2O. Stir at 60°C for 15-20 min. Add droplets of 1 M NaOH until solution turns clear. Add H2O to a final volume of 500 ml. Filter with a NalgeneTM filter unit and freeze aliquots for storage (-20°C). Thaw aliquots at 60°C for use, the solution should be clear. Fixative working solution (200 ml): 0.36 g NaH2PO4∙H2O.
The amount of glutaraldehyde in this fixing solution can be reduced to 0.2% when samples should be processed for immunoelectron microscopy. In case of sensitive antigens, glutaraldehyde can also be omitted, but this will result in a less-preserved ultrastructure. An excellent and detailed protocol for cryosectioning according to Tokuyasu (1973) and immunolabeling of thawed cryosections is provided by Peters and Pierson (2008) and therefore not explained further here. b "Perfixol": 5% Glutaraldehyde/4% Formaldehyde in Cacodylate Buffer pH 7.2 According to Griffiths et al. (1981 Buffer (0.08 M Na-cacodylate, pH 7.2): Dissolve 8.56 g Na-cacodylate in 450 ml H2O. Adjust pH to 7.2 with 1 M HCl. Add H2O to a final volume of 500 ml. Fixative working solution (500 ml): 150 ml 0.08 M cacodylate buffer 250 ml 8% paraformaldehyde in H2O (final: 4%) 100 ml glutaraldehyde 25% in H2O, EM-grade (final: 5%) 0.33 g CaCl2∙2H2O Filter with a NalgeneTM filter, adjust pH to 7.2 if necessary. Embryo dishes (preferably black, if used for small, quasi-transparent samples) or crystallization dishes (e.g., from Agar, Stansted, U.K.); -0.2 M cacodylate buffer (contains arsenic compounds!), optionally supplemented with 2 mM sucrose; 0.05-0.1 M phosphate buffer, optionally supplemented with 2 mM sucrose and/or 0.02 mM magnesium sulfate; 0.001 M Tris-HCl, 1 mM CaCl2, 0.1 mM MgCl2, 0.1 mM KCl, 1 mM NaH2CO3, pH 7.8 (Hydra culture medium); Urethane was from Sigma-Aldrich, Inc (St Louis, U.S.A.); Paraformaldehyde (Sigma-Aldrich), glutaraldehyde, OsO4 crystals, epoxy resins (Epon, Spurr`s) were from Sigma-Aldrich (St Louis, MO), Agar-Scientific (Stansted, England), EMS (Hatfield, PA), Polysciences (Warrington, PE), or Ted Pella (Redding, CA). B Chemical Fixation 1 Chemicals (be aware that most of the reagents are more or less toxic and/or hazardous to health; for their safe use and disposal consult the relevant Material Safety Data Sheets) 0.05-0.2 M cacodylate buffer (contains arsenic compounds!), optionally supplemented with varying concentrations of sucrose. 0.05-0.1 M phosphate buffer, optionally supplemented with varying concentrations of sucrose and/or magnesium sulfate. Hydra culture medium: 0.001 M Tris-HCl, 1 mM CaCl2, 0.1 mM MgCl2, 0.1 mM KCl, 1 mM NaH2CO3; pH 7.8 (all Sigma-Aldrich or Merck). Urethane and 1-phenoxy-2-propanol (Sigma-Aldrich). Paraformaldehyde, potassium dichromate, as well as glutaraldehyde, OsO4 crystals, epoxy resins (Epon, Spurr`s) from Sigma-Aldrich, Agar (Stansted, U.K.), EMS (Hatfield, PA, U.S.A.), Polysciences (Warrington, PE, U.S.A.), or Ted Pella (Redding, CA, U.S.A.), LR-White acrylic resin from Sigma-Aldrich or London Resin Co (Woking, Surrey, U.K.). 2 Tools For specimen handling, embryo dishes (preferably black, if used for small, quasi-transparent species) or crystallization dishes (e.g., from Agar) and fine glass or small plastic pipettes were used.

•3.1 ParaFormaldehyde
Paraformaldehyde is the informal name of polyoxymethylene, a polymer of formaldehyde (also known by many other and confusing names, such as ‘paraform`, ‘formagene`, ‘para`, ‘polyoxymethane`). It is slowly formed as a white precipitate by condensation from the predominant species methanediol (formaldehyde hydrate) in solutions of formaldehyde (which may also be called ‘formalin`, ‘formal`, or ‘formalose`) on standing, in an equilibrium (Fig. 3.1). The solution is predominantly of oligomers, but when n becomes large enough the material becomes sufficiently insoluble as to precipitate, when the condensation may still continue. The resulting solid may have n range from ~ 8 to 100, or more. The reaction is driven to the left, to release formaldehyde, by a low concentration of formaldehyde, and accelerated by acidic or alkaline conditions. Solid paraformaldehyde smells plainly of the monomer (b.p. - 21 °C), so it is essentially a convenient means of delivering formaldehyde slowly.
Formaldehyde reacts (as the hydrate) with proteins, cross-linking them, by condensing with secondary amines at the peptide linkage (Fig. 27§3.5), and with the primary amines at the N-terminal or the side chains of arginine, histidine and lysine residues to create irreversible methylene bridges (Fig. 3.2).[48][49] Similar reactions also occur with the -SH group of cysteine residues, and the amines of DNA and RNA. Whilst such reactions are useful when tissue needs to be fixed for histological work, or simply museum specimens (or cadavers for dissection), clearly they are problematic in living systems. Indeed, formaldehyde is now known variously to be allergenic, generally toxic, extremely cytotoxic, mutagenic and carcinogenic, and so is increasingly under strict control in many contexts. Inhalation of the vapour must be avoided (the vapour pressure is high[50]). It is implicated as an asthma-inducer or exacerbator, and is a major component of house-fire smoke and photochemical smog. The use of paraformaldehyde, therefore, as an ingredient of endodontic cements[51] - to achieve so-called "mummification" (i.e. fixed tissue) - is now considered inappropriate (although not without controversy[52]). The inclusion of alkaline ingredients only serves to accelerate the hydrolysis and depolymerization. Sterilization would, of course, occur anyway. Formaldehyde itself is also used.[53] The acid hydrolysis of hexamethylene tetramine[54] (Fig. 3.3) (solubility in water ~ 850 g/L, 20 °C), an ingredient of one known endodontic product,[55] also yields formaldehyde.

Formaldehyde was formerly used as a dentine desensitizing agent, and has even been included in toothpastes (with a pungent taste!) for the same supposed effect, although unsuccessfully.[56][57]

Formaldehyde is also formed as a by-product of free-radical polymerization of methacrylates (as in filled resins) in the presence of oxygen (6§6),[58] and in this context may be a contributory factor to adverse reactions,[59] being released slowly over a long period, presumably as the peroxides break down. This might also occur with acrylic denture bases as an irritant for denture stomatitis or ‘sore mouth` in addition to residual MMA (5§2.7).[60] Since the precursor peroxides are not thermally stable, in heat-cured materials these will be decomposed and the resulting formaldehyde may escape, if allowed sufficient time. In cold-cure materials (5§3), this decomposition will not occur, and the available concentration will therefore be higher. Similar effects will occur in any chemically-similar system, such as so-called "resin-modified" GI cement (9§8.9).[61][62] This underlines the value of removing the oxygen-inhibited layer wherever possible.

Degradation of cyanoacrylates may proceed through depolymerization by hydrolysis (10§6.2), by the simple hydrolysis of the ester first, but another reaction occurs that also generates formaldehyde (Fig. 3.4).[63] Again, this may lead to the irritation of living tissue.

There is much concern over human exposure to formaldehyde because of the possibility of adverse reactions, despite the fact that it is present (at a low concentration, generally) in the environment from a number of natural sources as well as being a normal and essential physiological metabolite in man at very low concentrations, where it is not toxic.[64]

Paraformaldehyde: To 1 liter doubly distilled H2O, add 40 g paraformaldehyde and 12.5 g Na2HPO4 Chromic sulfuric acid: Combine 1800 ml sulfuric acid and 5 ml Chromerge (chromic sulfuric acid cleaning solution, J. T. Baker Chemical Co., Phillipsburg, NJ). Reuse until solution turns green Subbing solution [1% (w/v) gelatin, 0.1% (w/v) chrome alum]: To 1 liter doubly distilled H2O, add 10 g gelatin (heated to dissolve). Then add 1 g chromium potassium sulfate (chrome alum) Mounting solution: Combine 1 ml subbing solution with 9 ml doubly distilled H2O Concentrated (0.25 M) sodium phosphate buffer stock solution: Combine 30 g Na2HPO4 and 5.35 g NaH2PO4 · H2O and bring to 1000 ml with doubly distilled H2O. Store refrigerated up to 3 months Sodium phosphate-buffered saline (0.01 M, working solution): Combine 40 ml concentrated sodium phosphate buffer stock, 8.5 g NaCl, and 960 ml doubly distilled H2O. Bring to pH 7.4 with HNO3 or NaOH Boric acid/sodium tetraborate buffer (0.2 M): Bring 0.2 M boric acid (0.62 g in 50 ml doubly distilled H2O) to pH 8.5 with 0.05 M sodium tetraborate (0.95 g sodium tetraborate in 50 ml doubly distilled H2O). Store at room temperature 1-3 months 11.4 mg allantoin 3 ml boric acid/sodium tetraborate buffer, pH 7.5 20.2 mg cupric nitrate 1.2 g silver nitrate 6.4 ml pure pyridine Pour into washed container, wrap in aluminum foil, and place in 40°C water bath for 20-30 min before adding slides

Ammoniacal silver: Dissolve 18 g silver nitrate completely in 97.65 ml doubly distilled H2O; add
47.7 ml 0.4% (w/v) sodium hydroxide (NaOH)
4.5 ml acetone

Note: Add just enough ammonia to clear the solution. Ammonia may lose its potency over time, so the precise amount required may vary. This is a critical step since it determines the degree of silver impregnation. Too much ammonia prevents silver impregnation and too little can cause impregnation of normal tissue 7 ml 1% (w/v) citric acid 100 ml 100% (v/v) ethanol 881 ml neutralized doubly distilled H2O Sodium thiosulfate: 250 ml of a 1.0% (w/v) solution Potassium ferricyanide: 250 ml of a 0.5% (w/v) solution Sodium hydroxide: 250 ml of a 0.4% (w/v) solution Citric acid: 250 ml of a 1.0% (w/v) solution Formalin (10%, v/v): Add 2 ml 37% commercial formaldehyde solution to 18 ml doubly distilled H2O

2.1 Reagents
Paraformaldehyde (PFA) (Sigma, P6148) 5 M NaCl (Sigma, S5150-1L) SDS (Sigma) 1 M Tris-Cl, pH 6.5 at 25°C (KD Medical) 1 M Tris-Cl, pH 8.0 at 25°C (KD Medical) KOH (Sigma) Triton X-100 (Sigma) 0.5 M EDTA (Sigma) 0.1 M EGTA (Sigma) Proteinase Inhibitor cocktail (Roche, 11 836 153 001) DNase/RNase-Free Distilled Water (Invitrogen, 10977-023) PBS (KD Medical) TE (KD Medical) 8 M LiCl (Sigma, L7026) IGEPAL-CA630 (Sigma, 18896) Sodium deoxycholate monohydrate (Sigma, D5670) NaHCO3 (Sigma, S5761) Dynabeads Protein G (Invitrogen, Cat no: 10004D) Proteinase K, 20 mg/mL (Thermo Fisher Scientific # 25530049) Anti-DMC1 antibody (Abcam, Ab 11054) MinElute PCR Cleanup Kit (Qiagen, 28004) TruSeq Nano DNA LT Library Preparation Kit (Illumina) T4 DNA polymerase (3 U/μL, New England Biolabs, M0203) DNA Polymerase I Large (Klenow) Fragment (5 U/μL, New England Biolabs, M0210) T4 Polynucleotide Kinase (PNK) (10 U/μL, New England Biolabs, M0201) Klenow fragment (3′ → 5′ exo-) (5 U/μL with 10 × NEBuffer 2, New England Biolabs, M0212) Quick ligation kit (New England Biolabs, M2200) T4 DNA Ligase Reaction Buffer (New England Biolabs, B0202) dATP and dNTPs (New England Biolabs) Qubit dsDNA HS Assay Kit (Thermo Fisher Scientific # Q32851) or Quant-iT PicoGreen dsDNA Assay Kit (Thermo Fisher Scientific, P7589) AMPureXP beads (Beckman Coulter) Solutions for Perfusion and Postfixation Depolymerized paraformaldehyde (4%) for perfusion: Combine 40 g of paraformaldehyde powder, 22.6 g of NaH2PO4, and 25.2 g of NaOH; adjust final volume to 1000 ml with distilled H2O, and adjust pH to 7.3; heat solution to 65°C and add drops of 10 N NaOH until solution clears. Let solution cool before use Phosphate-buffered saline (PBS) (10 ×): Combine 90 g of NaCl, 1.22 g of KH2PO4, and 8.15 g of Na2PO4; adjust final volume to 1000 ml with distilled H2O, and adjust pH to 7.4. (To make 1 × PBS, dilute 100 ml of 10 × PBS in 900 ml of distilled H2O)
Sucrose medium: Combine the following: Turkey / TurkishHızlı Satın AlmaFavorilerBize Ulaşın Tümü ürün, CAS, Anahtar kelime, ... arama Arama GirişKayıt Ol 0 Sepet Home Ürünler Hizmetler Dokümanlar Sorumluluk Destek Hakkımızda About Our Brands Home>Reagents, Chemicals and Labware>Organic Synthesis>Organic Synthesis Product Groups>Aldehydes>Aliphatic and Araliphatic Aldehydes>Paraformaldehyde 818715 Sigma-Aldrich Paraformaldehyde Download Zoom

RTECS   RV0540000
Storage class   4.1B Flammable solid hazardous materials
WGK   WGK 2 obviously hazardous to water
Disposal   3
Relatively unreactive organic reagents should be collected in container A. If halogenated, they should be collected in container B. For solid residues use container C.
Safety Information
Hazard Symbols   Hazard SymbolsToxic
Categories of danger   harmful, irritant, carcinogenic, sensitizing
R Phrase   R 45-20/22-37/38-68-41-43
May cause cancer.Also harmful by inhalation and if swallowed.Irritating to respiratory system and skin.Possible risk of irreversible effects.Risk of serious damage to eyes.May cause sensitisation by skin contact.
S Phrase   S 22-26-36/37-45-53
Do not breathe dust.In case of contact with eyes, rinse immediately with plenty of water and seek medical advice.Wear suitable protective clothing and gloves.In case of accident or if you feel unwell, seek medical advice immediately (show the label where possible).Avoid exposure - obtain special instructions before use.
Storage and Shipping Information
Storage   Store at <= 20°C.
Transport Information
Declaration (railroad and road) ADR, RID   UN 2213 , 4.1, III
Declaration (transport by air) IATA-DGR   UN 2213 , 4.1, III
Declaration (transport by sea) IMDG-Code   UN 2213 , 4.1, III
Specifications
Assay (acidimetric)   ≥ 95.0 %
Identity (IR)   passes test
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818715 Sigma-Aldrich
Paraformaldehyde
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9. Paraformaldehyde
9.1 Open containers of paraformaldehyde crystals or powder dissolved in solution give off
formaldehyde vapors. Users should minimize exposures to paraformaldehyde and avoid the
weighing and dissolving steps by purchasing "ready to use" buffered formalin solutions in
concentrations ranging from 2 to 10 percent and using these solutions in chemical fume hoods.
University of Pittsburgh
Safety Manual EH&S Guideline Number: 04-007
Subject:
FORMALDEHYDE AND
PARAFORMALDEHYDE
Effective Date
07/30/14 Page 3 of 3
9.2 Paraformaldehyde is moderately toxic by skin contact. It has recently been designated as a
probable human carcinogen. Skin contact with paraformaldehyde may cause itching and rash that
may lead to skin allergy upon repeated exposure. It has also been reported to cause reproductive
and mutagenic problems in humans exposed long term.
9.3 Breathing paraformaldehyde powders or vapors will irritate the nose and throat after prolonged
exposure causing a cough, shortness of breath and possible lung damage including pulmonary
edema. Chronic inhalation exposures may lead to an asthmatic or allergic condition with
wheezing and chest tightness. Acute exposure may cause irritation to the eyes and respiratory
tract.
9.4 All weighing and handling of paraformaldehyde should be done with adequate ventilation using
chemicals fume hoods, vented balance enclosures or other local exhaust ventilation. Pre-weighed
packets or purchase of prepared formalin solutions should be substituted if possible to minimize
potential exposures.
10. Respiratory protection from formaldehyde vapors should not be necessary if other control measures
are utilized. If ventilation measures are inadequate or not available, use of respiratory protection may
be warranted. Consult EH&S. All users of respiratory protection must be enrolled in the University
Respiratory Protection Program. Particulate filtering respirators (dust masks) provide no protection
against formaldehyde vapors.
11. Paraformaldehyde or concentrated formalin solutions may react violently with strong oxidizing
agents, ammonia, strong alkalis, isocyanates, peracids, anhydrides and inorganic acids. Contact and
storage with these reactive chemicals should be avoided.
12. Paraformaldehyde and formalin solutions should be stored in a cool, well ventilated area away from
heat, sunlight and moisture. Vapors emitting from paraformaldehyde and formalin solutions are
flammable, and the Guidelines for the Storage and use of Flammable Liquids found in this manual
apply.
Paraformaldehyde possesses the common characteristics with a wide range of applications. Paraformaldehyde is the smallest solid form of liquid formaldehyde, formed by the polymerization of formaldehyde with a typical degree of polymerization of 8-100 units. As paraformaldehyde is basically a condensed form of formaldehyde, it possesses the common characteristics with a wide range of applications. Advantages of paraformaldehyde in resin production as compared to aqueous formaldehyde Paraformaldehyde does not need to be dissolved in water in order to take part in a chemical reaction. Higher productivity from existing equipment and less water to be removed from the resin product. Paraformaldehyde made with very low acid content in a chemical resistant environment can prevent the formation of acidic by-products.
We offer a prilled form, which is stable and very easy to store. Paraformaldehyde storage is less expensive than the storage of formaldehyde solution, which requires expensive tanks and which may need stabilization or be kept warm. It eliminates the risk of transporting liquid formalin, which is notoriously dangerous. Perfect for small uses straight from the bag. Use of paraformaldehyde is convenient and safe. It avoids pollution arising from the disposal of the distillate obtained in the thermosetting resin production which is contaminated with organic matter. Typical Properties Color White Number 30525-89-4 Appearance Free Flowing Prilled Molecular Formula OH-(CH2O)n-H where n=8 to 100 units Paraformaldehyde Content 92% ± 1% / 96% ± 1% Water Content 8% ± 1% / 4% ± 1% Reactivity 2 - 8 min Mean Particle Size 250 - 350 µm Ash 0.01 - 0.05% Bulk Density 650 - 850 kg/m3 Melting Point 120 - 175 C Ph 4 - 7 Flammability combustible, with flash point (tag open cup) of about 93 C Vapour Pressure varies with air humidity, being between 23 and 26 mmHg at 25 CApplications  Resins Industry The most important use of paraformaldehyde is as a source of formaldehyde groups in the production of many thermosetting resins, together with phenol, urea, melamine, resorcinol and other similar reagents. These resins are used as moulding powders; in the wood industry as glues for chipboard, plywood and furniture; as bonding resins for brakes, abrasives and foundry dyes; as finishing resins for paper and textiles; as driers and glossing agents for paints; as insulating varnishes for electrical parts.

Disinfectant
Paraformaldehyde generates formaldehyde gas when it is depolymerized by heating. The depolymerized material reacts with the moisture in the air to form formaldehyde gas. This process is used for the decontamination of large spaced and laminar-flow biological safety cabinets when maintenance work or filter changes require access to the sealed portion of the cabinet. It is used in the poultry industry as a disinfectant in the hatcheries, and cattle and sheep industry for sanitizing the bedding in the sheds. It releases formaldehyde gas when the temperatures increase. It reduces contamination levels caused by moulds, viruses and bacteria. Agriculture and Pesticides Most paraformaldehyde consumed by the agrochemicals industry is for the herbicides such as bismerthiazol, butachlor, acetochlor, glyphosate, and machete. Paraformaldehyde, Formadehyde and Formalin Confused? Formaldehyde is CH2O, the simplest aldehyde. Formalin is the name for saturated (37%) formaldehyde solution. Thus, a protocol calling for 10% formalin is roughly equivalent to 4% formaldehyde. Beware though, that some solutions have methanol in them to stop polymerization but this could have a negative effect on your sample. Paraformaldehyde (PFA) is actually polymerized formaldehyde. "Pure", methanol-free formaldehyde can be made by heating the solid PFA. This might be called paraformaldehyde, but it actually isn`t because it`s not the polymer form. You can buy EM grade formaldehyde or you can make your own . . .
Making Paraformaldehyde Solution 4% paraformaldehyde is usually made in PBS or TBS at 70 °C with several drops of 5N NaOH to help clarify the solution. Prepare 4% paraformaldehyde solution in a chemical hood if you don`t want to be slightly fixed yourself.
Often PFA stocks have insoluble impurities and it`s best that these be removed via a quick spin in a table-top centrifuge or by passing the prepared solution through a filter syringe. It is also important to realize that the efficacy and impurity content of powdered PFA can vary greatly from lot number to lot number of reagent. Don`t be surprised if your fixation concentrations & conditions may need to be tweeked when you open a new bottle of PFA. You can store the solution but all solutions go bad with time so using freshly prepared solutions that are colorless is often best. (Storing aliquotes at -20 °C and using them over a couple of months is typical). SDS Paraformaldehyde, 96%, ACROS OrganicsTM Available on GSA/VA Contract for Federal Government customers only. 25g, Plastic bottle Quantity: 25g 500g 1kg 3kg 10kg Packaging: Plastic bottle Plastic drum CAS 30525-89-4 Molecular Formula CH2O Molecular Weight (g/mol) 30.026 InChI Key WSFSSNUMVMOOMR-UHFFFAOYSA-N Synonym formalin,methanal,formol,methylene oxide,paraformaldehyde,oxomethane,paraform,formic aldehyde,oxymethylene,methyl aldehydeShow More PubChem CID 712 ChEBI CHEBI:16842 IUPAC Name formaldehyde SMILES C=O Catalog No.AC416780250 Mfr: Acros Organics416780250 $15.65 / Each Request bulk or custom formats Qty Check Availability Add to cart Description This product(s) resides on a Fisher Scientific GSA or VA contract. If you are viewing this page as a nonregistered user, the price(s) displayed is List Price. To view your GSA or VA contract pricing, log in using your account number, or become a registered user by contacting one of our Customer Service teams. You can also view your contract price by searching for this item(s) on GSA Advantage. To place an order, contact Fisher Scientific Customer Service.

Specifications Packaging Plastic bottle Melting Point 120.0°C to 170.0°C Flash Point 71°C Quantity 25g Ash 0.02% max. pH 4.0 to 5.5 (10% suspension) Additional Information Vapor Pressure: 1.2mmHg at 25°C Free Acid 0.03% max. Decomposition Information 260°C Infrared Spectrum Authentic Show More Certificates Certificate of Analysis (30)

Lot Number B0148337Lot Number A0409947Lot Number A0408957Lot Number B0147499Lot Number B0146924Lot Number B0146924ALot Number A0404674Lot Number A0401853Lot Number B0146648Lot Number A0400640Lot Number B0145208Lot Number B0145986
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0% Paraformaldehyde (Formaldehyde) Aqueous Solution, EM Grade, different packing units

Paraformaldehyde - Methanol free solution. A more efficient and rapid penetrant fixative used in combination with Glutaraldehyde and Acrolein fixatives. Easy to break, prescored, 10 ml ampoules sealed under inert gas, or 100 ml bottles.
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20% Paraformaldehyde (Formaldehyde) Aqueous Solution, EM Grade, 10x 10ml
20% Paraformaldehyde (Formaldehyde) Aqueous Solution, EM Grade, 100ml
E15713-S
Paraformaldehyde (Formaldehyde) Aqueous Solution, EM Grade, different packing units
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Specification Datasheet Related Products & Accessories
Type   Formaldehyde
Symbol GHS
S08
Signal word   Warning
Hazard statements   H302_H312, Harmful if swallowed, in contact with skin or if inhaledH315, Causes skin irritation.H317, May cause an allergic skin reaction.H319, Causes serious eye irritation.H335, May cause respiratory irritation.H351Suspected of causing cancer .
Precautionary statements   P261, Avoid breathing dust/fume/gas/mist/vapours/sprayP280, Wear protective gloves/protective clothing/eye protection/face protectionP281, Use personal protective equipment as requiredP305_351, IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses if present and easy to do - continue rinsingP405Store locked up
Mandatory sign
Protective gloves
Tightly sealed goggles
Condition   fluid
Delution   20%
Shipping Class   Hazardous Good LQ
Storage Temperature   RT
Application   EM
Datasheet   SDS english
Description
United States Patent 1O 5 Application september 25, 1953, Serial No. 382,450 s 9Claims. (Cl. 260-615) V p This invention relates principally to a new and novel process for the 1 production of paraformaldehyde. More particularly, this invention relates to a new and novel `process for the production of paraformaldehyde in a formexhibiting a greater reactivity and a greater solubility than paraformaldehyde prepared by presently known commercial procedures. As is well known, formaldehyde is an extremely important chemical raw material. This aldehyde is produc`d in enormous quantities, either by the partial oxidation of natural gas or by the partial oxidation of methanol. Formaldehyde is a gas (B. P. -2l C. which l ven at the boiling point slowly changes to the cyclic jtrimer, trioxymethylene, the rate of this polymerization reaction increasing rapidly with increasing temperature. lAccordingly, the large scale preparation,-transportation an`dfstor age of formaldehyde for subsequent use in chemical syntheses is not practical.
Fortunately, formaldehyde is very soluble in water and an aqueous solution containing 37% formaldehyde by weight (formalin) is the form in which this aldehydemost frequently appears in commerce. However, for: malin leaves muchto be desired as a chemical raw material. The solution is corrosive and is not too stable in storage, especially at temperatures `above and below ordinary roomtemperatures. In addition,`due to the low concentration of formaldehyde in formalin the rates of reaction in syntheses employing formalin are frequently quite low and thesize of .a batch that can be processed in a given piece of equipment is small. Since formalin contains over 60% by weight of water it is necessary to transport, handle and store this large amount of solvent.

To offset the corrosivenature of formalin, this material is usually shipped in insulated resin lined tank cars or in resin lined drums. At the point of consumption, handling of the solution should be through chemical rubber hose or corrosion resistant pipe to storage fa:

T cilities constructed of stainless steel (type 304 or, preferably, types 316 or 317), aluminum (types 25, 38, 528

or 61S-T) or mild steel coated with a suitable resin. Obviously, these requirements add greatly to the cost of transporting, handling and storing formalin. It should be noted that these requirements with respect to materials of construction are necessary not only to prevent corrosion of equipment but also to avoid contamination of the formalin with the products of corrosion. Traces of many metal salts, for example, iron salts, greatly reduce the stability of formalin.

Formalin is quite unstable. To enhance the stability l of the solution it is common practice to incorporate methanol therein as an inhibitor. For tank car shipments about 7% methanol is commonly employed while drum shipments commonly contain 1214% methanol. Methanol is a valuable chemical and chemical raw materialand is, in fact, one of the major raw materials for the production of formaldehyde. The use of such large amounts of-methanol as an inhibitor is a distinct eco nomic waste and represents an appreciable item in the a 1,"? MN -n M...

cost of the so inhibited formalin. The stability of. inhibited formalin still leaves much to be desired. When exposed to cold weather paraformaldehyde separates from the solution. After relatively short exposure to but moderately low temperatures the separated paraformaldehyde may be dissolved by heating the solution but if the formalin is in resin lined containers care must be taken not to heat the solution above 60C. lest the resin lining be injured. Prolonged exposure to very low temperatures results in the separation of large quantities of paraformaldehyde in a formthat is impossible to dissolve. High temperature storage is equally undesirable.` At high temperatures the acidity of the solution increases, due probably to the enhanced rate of oxidation of formaldehyde to formic acid. The increased acidity accelerates many decomposition reactions of formaldehyde. For example, the union of formaldehyde with methanol to form methylal is accelerated by acids, especially in the presence of, traces of metal salts. Also, under acidic conditions and at elevated temperatures the Cannizzaro reaction may occur resulting in the formation of formic acid (which stillfurther increases acidity) and methanol (which may react to form additional methylal). For all these reasons it is generally recommended that even inhibited formalin be stored for as short a period as possible atatemperature above 15 C. and below 40 C. This generally requires that storage containers be provided withheating coils and some means for cooling.

The `high water content (63% by weight) of