Particulates Not Otherwise Classified (PNOC) (Pi)

According to Decree 280-2024 published on February 28, 2024, in the Gazette officielle du Québec, the amendment to the Appendix 1 of the Regulation respecting occupational health and safety (RSST, RLRQ, c. S-2.1, r. 13) will come into force on March 14, 2024. These regulatory changes have not yet been incorporated into the current Substance Data Sheets of the Sampling Guide for Air Contaminants in the Workplace. An update is currently underway and will be available as soon as possible. Consequently, the information contained in the data sheets of substances modified or added in Decree 280-2024 is partially inaccurate or incomplete. Please consult our infoLABO (in French only) for more details. Please contact our client service: [email protected] for further information.

Particulates Not Otherwise Classified (PNOC) (Pi) (See Remark)

French name in the regulation: Poussières non-classifiées autrement (PNCA) (Pi)

Synonyms: Poussières nuisibles

Exposure Standards in RROHS regulation

Permissible exposure values (PEV)

	ppm	mg/m³	f/cc	Notes
TWAEV	-	10	-	Pi
STEV	-	-	-	-
Ceiling	-	-	-	-

Carcinogenicity		Sensitizer
Simple asphyxiant		Percutaneous
Prohibited use		Prohibited recirculation
Minimum exposure		Explosion hazard
Ototoxic

Remark :	PARTICULATES NOT OTHERWISE CLASSIFIED (PNOC): Particulates present in the air that meet the following conditions are considered Particulates Not Otherwise Classified (PNOC) or nuisance particulates: (1) no permissible exposure value is provided for them in Part 1 of Schedule I to this Regulation; (2) they are insoluble or poorly soluble in water; (3) their toxicity is low and they have no effect other than lung overload or mechanical irritation.

Remark :

PARTICULATES NOT OTHERWISE CLASSIFIED (PNOC):

Particulates present in the air that meet the following conditions are considered Particulates Not Otherwise Classified (PNOC) or nuisance particulates:

(1) no permissible exposure value is provided for them in Part 1 of Schedule I to this Regulation;

(2) they are insoluble or poorly soluble in water;

(3) their toxicity is low and they have no effect other than lung overload or mechanical irritation.

TWA adjustment for unusual work schedules

1C : No adjustment

CNESST – Toxicological Index Service

Consult REPTOX file: Particulates Not Otherwise Classified (PNOC)(Pi)

Analysis:

Weight measurement for inhalable and respirable dusts

Method: IRSST - 424

Sampling protocol

Sampling device:
Sampling media required:

#IRSST	Description
924	Plastic IOM, PVC filter, 5 µm, 25 mm

Parameters:
Flow rate: 2,0 L/min
TWA sampling volume: 480 L
STEL sampling volume: -

Analytical protocol

Principle: Gravimetric measurement (Grav)
Remarks: The minimum reported value (MRV) is 60 µg for respirable dusts and 200 µg for inhalable dusts. The analytical uncertainty (CVa) is 2.3% for respirable dusts and 3.4% for inhalable dusts. Additional information is available in Info-Labo 1991-03 and in Info-Labo 2019-06. The weight measurement method for dusts is by definition non-specific.

Reference

IRSST. "Détermination simultanée des poussières de fraction respirable et inhalable dans l'air". Méthode 424. Non publié.