The occupational hygienist (OH) has made some initial measurements of dust levels and gathered other information relating to exposure of workers to vitamin C powder. All of this information is provided in supporting document 1. Looking at the information in section 1 of supporting document 1.

comment on what the numerical information indicates. (14)

Supporting document 1

Information relevant to workers exposure to vitamin C powder

SECTION 1

Fixed place (static) measurements next to charging point of Mixing Vessel E

All measurements taken over a 3-hour period from 09:00 12:00 on each day

Date	Dust level 8-hour TWA
24/4/23	25 mg/m3
25/4/23	15 mg/m3
26/4/23	11 mg/m3
27/4/23	8 mg/m3
28/4/23	20 mg/m3

Weekly Production Schedule for Mixing Vessel E

Date	Morning (Early)	Afternoon (Late)
24/4/23	Vitamin C product	Vitamin C product
25/4/23	Vitamin C product	Clean and maintenance
26/4/23	Vito-iron liquid product	Vito-iron liquid product
27/4/23	Vito-iron liquid product	Clean and maintenance
28/4/23	Vitamin C product	Vitamin C product

SECTION 2

Personal exposure dust measurements for workers at Mixing Vessel E charging point

Date	Worker	Total sample period	Dust level during sampling period
24/4/23	Worker 1	09.00 10.00	12 mg/m3
28/4/23	Worker 2	15.00 16.00	10 mg/m3

Particle Size Distribution Data for vitamin C powder

Particle Size (microns)	% by weight	Cumulative % by weight
<5*	5	5
5 7*	15	20
7 10*	20	40
10 15	25	65
15 30	20	85
30 50	10	95
50 100	5	100

(* Supplier information indicates this represents the respirable fraction of the vitamin C powder raw material)